On 7 April 1792, the Sukkel family was waiting to unload their boat at the Keulse Waag in Amsterdam amidst other ships coming from different German states via the Rhine. When the customs officers arrived to inspect their vessel, the family reacted aggressively and even became violent. Madam Sukkel hit one officer with a broomstick and together with her husband and children threw him of their boat, scaring off his customs colleagues.¹ What this family wanted to hide from these officials and whether there were further repercussions remains unknown, but we do know what they carried up the Rhine from Amsterdam a year later. The cargo consisted primarily of different sorts of sugar. On board was also coffee from Java, from Suriname, and the relatively cheap coffee from Saint Domingue, in particular, which was in high demand. Tobacco from Virginia and Puerto Rico, rice, and pepper could be found among the cargo of this skipper family, too. Actually, a load of Dutch Edam cheese was the only item not from overseas. Most of these were colonial wares produced by enslaved persons on the other side of the Atlantic Ocean.² The ancestors of the Sukkels, for instance – had they been engaged in Rhine trade, too – would have carried a very different cargo. Dutch skippers had imported oak wood and Rhenish wine over the river for ages, in addition to bringing salt and fishery products to Germany.³ This ancient regional trade became thoroughly transformed over the eighteenth century, and it happened especially during the decades before the incident with the Sukkels.

The Rhine as a gateway from the Dutch Republic to the German hinterland – comprising most of contemporary Germany except for the coastal towns like Hamburg and Bremen – is usually associated with emergence of the Ruhr industry over the course of the nineteenth century, but its origins lay further back in history with the eighteenth-century trade in commodities such as coffee, sugar, indigo, and tobacco. Likewise, literature on the Rhine trade almost exclusively focuses on later periods, while research on colonial commodities and literature on early modern trade and transport in general pay little attention to river trade.⁴ Nonetheless, it has been observed that German states became an increasingly important destination for Dutch re-exports. Johan de Vries found that colonial wares made up 70 percent of all exports from the Dutch Republic via the Sound and the Rhine by 1790.⁵ Jan de Vries and Ad van der Woude pointed out that in the eighteenth century the expanding shipping of colonial goods over the Rhine River to the German countries was one of the few growth sectors of the Dutch economy, when important sectors were stagnant or in decline and Dutch exports to the Baltic region suffered from growing competition. De Vries and Van der Woude see the growing importance of Dutch Rhine trade in the late eighteenth century as part of a reorientation of Dutch commercial economy from a Baltic-Mediterranean axis towards an Atlantic-German axis which remained important until well into the twentieth century.⁶

This article aims to further substantiate these observations by bringing together the scattered data on the content, volume, and value of the upstream Rhine trade in the eighteenth century. Using sources pertaining to different locations along the Rhine that were created independently of each other, I will argue that upstream Rhine trade grew substantially indeed both in volume and value, and I will provide more detail on when this growth took off and on the contents of this trade. From these findings, I will conclude that the growing quantities of the upstream Rhine trade is directly related to the booming Atlantic commerce, particularly with slave-based production and trade. The growth of this Rhine trade did not follow a linear slope but took off in the 1750s and 1760s, after which it stayed at this high level. Not only did the Dutch Rhine trade grow as part of a reorientation of the Dutch economy, but it was also an increase linked to the considerable growth of the Dutch plantations in Suriname and the Guyanas and particularly to the booming French slavery complex in the Caribbean during the same period.

This analysis thus links the economic debates about the reorientation of the Dutch economy over the course of the eighteenth century to the question of how the orientation to the Atlantic contributed to economic growth and structural change of northwestern Europe, not to mention how the Atlantic commerce might have been a factor in the Industrial Revolution, as Eric Williams has argued.⁷ Whatever the precise effects may have been, there is ample literature emphasizing the importance of Atlantic commerce for England, France, and the city-state of Hamburg.⁸ Moreover, as a result of their cliometric exercise, Acemoğlu, Johnson, and Robinson found a strong correlation between the growth of Atlantic commerce and economic growth in northwestern Europe.⁹

Nonetheless, a dwindling but still influential trend in historiography has maintained that European economic development had little to do with Atlantic trade and slave-based activities and had, rather, issued from internal dynamics.¹⁰ This article contributes to questioning this orientation by showing how crucial Atlantic slave-based commodities have been to the dynamics of the intra-European trade on the Rhine. By doing so, it contributes to a countermovement in historical research that not only provides evidence that Atlantic connections mattered to European economies but also (re)addresses the question of slavery’s impact on European development more broadly, as previously described in the introduction of the special issue of Slavery and Abolition.¹¹ In the same issue, Brandon and Bosma showed that as much as 40 percent of the growth of the economy of Holland in the decades around 1770 can be traced back to Atlantic slavery.¹² These recent findings and arguments about the importance of slavery to Europe’s most advanced economies, and that of the Dutch Republic in particular, also underscore the need to obtain a clearer picture of the eighteenth century Rhine trade.¹³ Looking at the Rhine trade also means following through the forward linkages of slave-based production beyond the (narrow) national scope: it adds a German connection. Results may reveal that the Atlantic slave-based economy had a none too minor role in the development of European internal economic integration.

Obviously, not all colonial wares were produced by enslaved persons, but we may assume that the goods coming from the Americas to the Dutch Republic relied overwhelmingly on slave labour.¹⁴ This article defines an item as ‘slave-based’ when one or more segments of the commodity chain involved enslaved labour. Sugar in this period was almost entirely of Atlantic provenance and slave-based, and sugar from France’s Saint Domingue dominated the Dutch and most of the German market.¹⁵ About 80 percent of the coffee came from Dutch and French slave-plantations, whereas another 20 percent was cultivated under forced conditions in Java’s Preanger residency.¹⁶ Rice and indigo were mainly Atlantic and thus slave-based products in the eighteenth century¹⁷ The provenance of tobacco is not always mentioned in the sources, but most of it was slave-based, since the importance of the local European tobacco declined once American slave-based Virginia tobacco conquered the European market and Dutch and German tobacco farmers returned to producing wheat.¹⁸ With regard to raw cotton arriving on the Dutch market, we may assume that it was slave-based to some extent. It came, for example, from the Dutch Guyanas, where planters were obliged to send it to Holland.¹⁹ Still, in the second half of eighteenth century most cotton in Europe came from Turkey, whereas cotton production in the southern U.S. only took off after the invention of the cotton gin in 1793.²⁰

In sum, the imports of colonial goods in the Dutch Republic were mainly slave-based and came from the Caribbean region, the Guyanas, Brazil, and North America. Still, there was an important category of ‘other colonial’ goods consisting of extra-European products obtained from Asia and Spanish America. In terms of value, the most important were the spices carried home by the VOC ships: the nutmeg and mace produced by slave labour on the Banda Islands, the cloves produced with compulsory labour in the Moluccas, the pepper that was cultivated under a variety of labour systems in Java and Sumatra, and cinnamon obtained through corvée labour in Sri Lanka.²¹ Furthermore, there were dyes like cochineal – mostly cultivated by indigenous labourers under Spanish colonial rule. Tea came from China in rather small volumes and was of marginal importance in terms of value.

A major handicap in reconstructing the Rhine trade in the eighteenth century is that toll registers were largely destroyed during the nineteenth century. Moreover, all early modern trade registers based on duties have reliability issues, which is also true for Convoyen en Licenten. Fraud with certain specific duties and thus cause for underregistration may have been rife, and this may have happened in particular with sugar. Export duties on raw sugar were very high in the Dutch Republic, so as to protect their own sugar industry. As a result, traders from Düsseldorf would try to list raw and semi-refined sugar as refined when they bought French Atlantic sugar for their local sugar industry. Biases caused by fraud, smuggling, and other failures in registration are therefore unavoidable. However, since each source exhibits its own type of biases, we can eliminate the worst outliers by combining sources and thus arrive at a plausible scenario.²²

The most important available source is the Convoyen en Licenten, which were export duties to be paid regionally in the Netherlands. Various registries of these have survived, but there are only a few years for which a complete eighteenth century set remains. Statistics have been preserved for the region of Amsterdam and the region of ‘De Maze’, which included Rotterdam – the most important sea harbour at the time – as well as Dordrecht, Schiedam, Nijmegen, Lillo, and Breda. Together these two sets of statistics cover an estimated 80 percent of the exports of the Dutch Republic. Different segments of these Convoyen en Licenten lists have been published by various historians and archivists in the twentieth century.²³ One problem with these lists, however, is that commodities are listed in different measures: some in value and others in various measures of volume or weight.

Annual national totals of trade had to be calculated on the basis of conversions, adding price data and combining the two sets of Convoyen en Licenten. For this purpose, I used years or destinations for which both value and weight of a specific commodity’s trade flows were provided by the Convoyen en Licenten (possibly an underestimation of values, as these had to be reported to customs). In addition, I applied the Posthumus prices (possibly an overestimation of value as these are bourse prices for commodities of good quality) and various sources on measures in order to convert almost all commodities listed to both value in guilders and weight in pounds.²⁴ This procedure results in an estimate of the share of slave-based commodities in the Rhine trade that is both more detailed and more transparent than the ones made by Johan de Vries.²⁵

In addition to the Convoyen en Licenten, we have the ‘Schenkenschanse Tol’. This is the Rhine toll booth at the Dutch side of the border near Emmerich. The registries are kept in Utrecht and have been largely preserved for the years 1651-1809. Since the Convoyen en Licenten were only preserved for a few years, this (almost) serial data on the Rhine trade is a great asset. Although neither quantities nor specific values of the cargoes were recorded in this toll, the amount paid by each ship passing is listed, and the annual revenues from the tolls were kept in a register.²⁶ I used a complete listing of these revenues – included in the master’s thesis by M.M. Verheul – for a trade proxy (similar to the way Van Zanden used the data provided by this masters’ thesis).²⁷ Since the toll ‘ordonnanties’ did survive as well, we know the various duties that were charged for specific items and how these duties changed over time.²⁸ The unit of taxation was sacks and barrels. Sugar and tobacco passed Schenkenschans as early as the seventeenth century, but coffee was only added to the list of taxed commodities in 1731.²⁹

The Schenkenschans’ revenue lists provide us with a unique and fairly reliable proxy for Rhine trade. The reliability of this proxy can moreover be validated by comparing it with another source, namely, the Cologne Crane Tax, which was used by Ulrich Pfister (see figure 2).³⁰ Both sources confirm independently of each other a strong upward trend from the mid-eighteenth century onwards, with a dip during the Fourth Anglo-Dutch War (1780-1784) and a serious depression starting after the Haitian Revolution of 1793. These findings are further corroborated by some more fragmented data from the Groote Gelderse Tol 1747, 1801-1806, and from the A’damse waagboeken, 1793-1800.³¹ Finally, the published letters from Emmerich by Scholz-Babies contain some statistics in letters written during the 1780-1783 period of the Fourth Anglo-Dutch War.³²

Again, Johan de Vries noted that the trade of the Amsterdam admiralty with the German hinterland exhibited a remarkable growth between 1753 and 1790, and also a surprisingly one-sided growth. Imports, he found, stagnated at more or less 5 to 5.3 million guilders but according to de Vries: ‘It is the export that shows an astonishing growth from 11.5 million guilders in 1753 to 29.1 million in 1790.’³³ Although one can make some caveats about the exactness of these figures, there is no way to deny that Rhine exports by the Dutch Republic grew substantially.³⁴ The Convoyen en Licenten indicate that the Amsterdam exports to the Rhine region tripled in weight from 18 to 55 million pounds. The value of Rhine trade registered by the Amsterdam admiralty increased from 10 to 25 million guilders and, even when deflated, it still amounts to a doubling trade value from 10 to 20 million (1753) guilder etween 1753 and 1790.³⁵ We thus see a doubling in trade value and a tripling in trade volume of upstream Rhine trade between 1753 and 1790 as indicated in figure 1.

While we can be quite confident about the data for 1753 and 1790, these obviously do not present a trend. In order to fruitfully combine these data with data from the Schenkenschanse Tol and the Cologne Crane Tax, we first need to rule out that these years are possibly outliers. Fortunately, the statistics in the Convoyen en Licenten provide us with data for more years: for Amsterdam there is data for 1789 and 1791 and for Maze for 1784 to 1793, and both confirm that 1790 was not a peak year. The possibility that 1753 is an exceptional, low year cannot be discounted, based on the surrounding years from the Convoyen en Licenten listings; still, Dutch imports in those years do not show any dip, and neither do particular political or economic circumstances suggest that there might be one.

While we can be confident about the aggregate growth, it was far from linear. The Schenkenschanse Tol revenues did not show a linear growth development between 1753 and 1790 (scenario a). It looks like Rhine trade increased especially fast between 1757 and 1770, as we can see below in figure 2. In this graph, I plotted the indices of the Schenkenschanse Tol revenues and the Cologne Crane Tax revenue. Both toll and tax revenues were originally given in guilders – the amount of the annual revenue was based on what ships paid at the toll or the crane at a particular moment. Therefore, both revenues are plotted with the base year 1690 to be made comparable, and for both a trendline is calculated showing the eleven-year moving average – in order to make visible the fact that trends were converging between roughly 1755 and 1770.

The first thing to note is that these toll revenues confirm the image of significant growth in Rhine trade between the years 1753 and 1790. In addition, the revenues of the Schenkenschanse Tol suggest a longer trend in the growth of Rhine trade since the late seventeenth century, which stablizes between 1760 and 1780. This steady state is followed by a short dip in revenues during the Fourth English-Dutch War (1780-1784), which in itself is a sign that re-exports of seaborne commodities are a large part of the exports. In the decade after the war revenues recovered rapidly only to decline sharply again in 1794, just after the Haitian Revolution. Between 1801 and 1806, Rhine trade moved towards the 1785 level, until the next deep crash of 1807-1811, caused by the Continental System. From Horlings we know that after 1811, Rhine trade recovered until 1816/1817, when the Rhine trade resumed its growth trend from the second half of the eighteenth century.³⁷ This rhythm already makes the relation with seaborne trade palpably clear.

Furthermore, both the development of the revenues of the Schenkenschanse Tol and the returns of the crane tax in Cologne (see figure 2) strongly suggest a rising trend over the eighteenth century. Both exhibited the same general annual growth trend of 1.3 percent between 1690 and 1789, and a sharp increase in the second half of the 1750s and early 1760s (roughly conciding with the Seven Years’ War [1756-1763]). A clear dip is apparent again during the Fourth Anglo-Dutch War 1780-1782, and in the French period after 1795. Both the revenues of the Cologne Crane Tax and the Schenkenschanse Tol show sharp declines during the Anglo-Dutch War and the French occupation of the Dutch Republic. Yet the Cologne Crane Tax maintains its growth trend, whereas the Schenkenschanse Tol exhibits a a slight decline.

We may assume that the sharp increase of both proxies indicates a real growth in Rhine trade in this period. Additionally, from the serial data from the Schenkenschanse Tol and Cologne Crane Tax, we can infer that Rhine trade grew rapidly between 1755 and 1770 and sustained the higher level. Is it a likely scenario that Rhine trade increased particularly fast in these fifteen years, because of two important separate developments: the Seven Years’ War and the staggering growth of Atlantic trade in slave-based products.

Whereas the Seven Years’ War involved all major European powers, the Dutch Republic remained neutral, which turned out to be highly beneficial to its commerce.³⁸ While Prussia and France were at war with each other, the Dutch brought the necessary foodstuffs to the German hinterland. The Schenkenschanse Tol registers show that in the year 1758, the Dutch grain exports over the Rhine were exceptionally high, while in the same year troops of Allied and French armies were on campaign on the west bank of the Rhine. The volume of single convoy of rye was as large as the city of Amsterdam normally consumed in one year.³⁹ The war was also favourable for Dutch re-exports of Atlantic commodities, particularly because the war circumstances impeded sugar and coffee shipments to Hamburg, which normally supplied some overseas products to inland Germany over land.⁴⁰ Martinique and Guadeloupe were occupied by the British and lost for the French. The vessels under neutral Dutch flag obtained a unique opportunity to ship off the sugar and other commodities from these Antillean islands.

The increase in trade volume on the Rhine was not temporary but stayed at high levels after the Seven Years’ War. From the late 1760s onwards Atlantic plantation production was vastly expanding. These decades saw major plantation investments in the Caribbean region and the rapid expansion of coffee cultivation.⁴¹ The relatively modest coffee production of Jamaica tripled in that decade and tripled again in the five years that followed.⁴² From the Dutch colony Surinam coffee exports increased steadily after 1755, reaching their highest level at an average three times higher in the 1770s.⁴³ In Saint Domingue, coffee production increased at a similar rate as that from Suriname between 1755 and 1767, but really soared during the last two decades before the Haitian Revolution (1793).⁴⁴ The next section will discuss how the staggering growth of coffee and sugar production in the Caribbean region impinged upon the Rhine trade.

While the Rhine trade grew substantially, the trade volume of slave-based commodities rose more than that of other commodities. In absolute terms, the weight of slave-based commodities traded up the Rhine from Amsterdam rose from 8 to 34 million pounds. In relative terms, the share of slave-based commodities in the Amsterdam Rhine trade as reported to Amsterdam admiralty in convoyen and licenten rose from about two fifths to almost two thirds of the weight (see table 1 and figure 1). Furthermore, the volume of slave-based exports grew; since the prices of these goods rose as well, the value of these exports increased exponentially. Coffee exports from Amsterdam along the Rhine developed from negligible in 1753 to about 6.6 million guilders in 1790, making up a major share of the total Rhine trade. Exports of sugar, indigo, cotton, and rice also grew both in volume and in value. Meanwhile, the shipment of goods up the Rhine that were produced in Europe and the Near East fell in value although not in value. Exports of sea products declined, while cheese exports grew.⁴⁵ In the category of clothing, we see a shift from valuable woollen and silk manufactures, towards re-exports of skins, as well as towards mostly Turkish raw cotton and cotton yarn.⁴⁶

In sum, the growth of Amsterdam Rhine trade in volume and value was entirely due to slave-based commodities, which offset declines in other rubrics.

While table 1 presents figures for Amsterdam, it is unlikely that those for Rotterdam would be very different. In fact, for the year 1790, it was possible to combine the Convoyen en Licenten data from both Amsterdam and the De Maze region (together these regions accounted for over 80 percent of Dutch exports), showing that about 64 percent of Dutch Rhine trade was slave-based in terms of value (see figure 3, and see also table i in the appendix).

Other evidence corroborates these data indicating the major share of the slave-based commodities in the Rhine trade. For the early nineteenth century more precise statistics are available, and these show a similar pattern.⁴⁷ Other evidence confirms the impression that from the mid-eighteenth century onwards, an increasing share of Rhine trade comprised colonial commodities. Several Rhine-related registries did list commodities on board. Although the respective volumes were not listed, they may still offer an impression. Verheul notes that initially fish is the most mentioned item in the registries of the Schenkenschanse Tol, but that this diminished after 1715, and that tobacco, sugar, and coffee appeared with increasing frequency.⁴⁸ This observation is corroborated by other sources. In 1747, the Gelderse tollen near Arnhem mentioned sugar and tobacco only sporadically and as a minor part of the loads coming from Amsterdam or Rotterdam, but sugar, coffee, and rice appeared frequently in 1801. In the Amsterdamse Waagboeken (Amsterdam Weigh House Books), the loads of the ships to Cologne were registered from 1793 onward and even list mostly slave-based goods.⁴⁹

Reports from the tolls at Emmerich (see appendix, figure i) confirm that slave-based wares were the most important goods shipped upstream in 1780, although one ought to be careful in using a war year to deduce general trends in trade.⁵⁰ Nonetheless, existing data points in the direction that coffee, sugar, indigo, and tobacco became the most important goods among the growing Dutch export trade on the Rhine.

This article looked at volume, value, and content of upstream Rhine trade in the eighteenth century and, specifically, at the role of slave-based commodities in its dynamics. On the basis of multiple sources, we can confirm earlier observations that Rhine trade grew substantially and steadily in the eighteenth century, in terms of both volume and value. Second, we can clearly discern a jump in growth between 1755-1770, which coincides with the plantation boom in the West Indies and a substantial growth of Dutch imports and, in particular, shipment of French slave-based commodities. This rise took off during the Seven Years’ War but was sustained afterwards. Third, the growth in value and quantity of upstream Rhine trade almost exclusively consisted of slave-based commodities. In the late eighteenth century, slave-based commodities may have amounted to two thirds of the value of Dutch exports via the Rhine.

These findings have important implications. First, the growth of slave-based Rhine exports was an important element in the reorientation of the Dutch economy, as has been suggested by De Vries and Van der Woude. This includes a shift from the Dutch trade in the Sound towards the Rhine trade. Second, in German regions along the Rhine, the consumption of slave-based commodities must have been considerable. On the eve of the French revolution, the Rhine region consumed about 10 percent of all western sugar, and about 17 percent of all coffee in Europe went up the Rhine (see figure ii and table ii in appendix).⁵¹ This part of Europe became increasingly connected to the Caribbean plantation complex, whereas Central and Eastern Europe became connected via Hamburg. Still, more research is needed to assess the interaction between the growth of intra-European and river trade in the eighteenth century and the growth of Atlantic commerce.

Moreover, there is yet another, broader implication. So far, the large size of intra-European and regional trade has been used to contradict the importance of extra-European trade, including Atlantic commerce. However, intra-European trade consisted increasingly of re-exports of slave-based products as well as supplies for the Atlantic production complexes. In French historiography, it has been pointed out that huge amounts of sugar, coffee, and indigo from Saint Domingue made up an increasing share of French’s imports and exports during this period.⁵² These slave-based commodities were largely exported to the ‘north’, and a substantial share of them went up the Rhine. The argument once famously made by O’Brien in 1982, which he later retracted, that non-European commerce was peripheral to Europe did indeed not pay attention to intra-European trade – which increasingly consisted of redistribution of colonial wares – nor to the fact that the growth of eighteenth century trade was largely based on these Atlantic items.⁵³ The growing Rhine trade of the second half of the eighteenth century demonstrates this phenomenon keenly. The catalyst that slave-based commodities provided for the Rhine trade calls for a wider perspective on the economic stimuli from slavery, one that looks beyond the profits of planters and beyond the colonial port cities. Extra-European trade gave a boost to intra-European trade. The crucial implication of this conclusion is that slavery and slave-based production, in contrast to what is still suggested often in historiography, clearly did contribute to European economic dynamics and growth.

Tamira Combrink (1982) is a lecturer in history at Vrije Universiteit Amsterdam and a research fellow at the International Institute for Social History in Amsterdam; she is writing a Ph.D. dissertation on Atlantic slave-based commodity chains in the Dutch Republic.