Rare map detailing the “ Impolicy of Slavery ”

Published by J. Cross, 18 Holborn, also Sold at Hatchard & Son, Piccadilly, J. & A. Arch, Cornhill, & Seelley & Son, Fleet Street, CHART OF THE WORLD, ON MERCATOR’S PROJECTION: ILLUSTRATIVE OF THE IMPOLICY OF SLAVERY. London, [ca. 1825.]
Engraving on laid paper with J. Whatman watermark, 7 ½”h x 8 ½”w at plate mark plus margins, wash color.

A rare persuasive map setting out an economic argument against slavery in the British Empire.

This simple map depicts the world on the Mercator projection, with land masses between 30 degrees north and south latitude in wash color. PJ Mode provides some background about map maker James Cropper and explains that the apparently simplicity conceals a somewhat subtle argument:

“This polemic map argues that import prohibitions and high duties on sugar were artificially inflating prices and inhibiting manufacturing in England. It was published by J. Cross, but the anonymous author of the map was soon identified as James Cropper, a successful and wealthy Quaker merchant, philanthropist and disciple of Adam Smith. Cropper was a major force in the anti-slavery movement and believed that eliminating tariff protections would lead to the end of slave labour in the West Indies.


“…. As explained in the legend, the tiny red dots in the Western Hemisphere represent Jamaica and the other West Indian sugar-producing colonies of England. While sugar may be grown in vast reaches of the world 30 degrees north and south of the equator—including India, shown in pink as “Hindostan”—import of that sugar [i.e., sugar produced outside the West Indies] into Britain was effectively barred, either directly or by prohibitive duties. Because sugar was an important commodity not only for food but for certain chemical processes, Cross argued that these restrictions, “imposed for the exclusive protection and support of slave cultivation in the West Indian colonies,” were constraining “British manufactures, to an extent that would give employment to all the destitute population of Ireland and Great Britain.” Apart from the employment opportunities lost, Cross put the cost of the trade barriers at 1.2 million pounds annually.


“Cropper had interests in East Indian sugar and therefore stood to benefit from the reduction of tariffs, which colored his role in the abolition movement. Nevertheless, Cropper “may be one of those occasional cases in which conduct is not primarily influenced by self interest.” (Major 2012, 306, quoting L. J. Ragatz; see Davis 1961) He we went on to play an important part in passage of the cornerstone Slavery Abolition Act of 1833 and in uniting the efforts of British and American anti-slavery organizations. “In Cropper’s mind the intensity of Quaker Quietism had fused with the economic optimism of Adam Smith. Anti-slavery confirmed this union, endowing laissez-faire with an immediate moral and spiritual purpose, and enriching his faith in the inevitability of human progress.” (David 173)” (PJ Mode, Persuasive Cartography, The PJ Mode Collection, #1039.01. See here for references cited in PJ’s text.)

Coming as it did from an arch-capitalist, Cropper’s economic argument seems to have been well received, as the map was republished a number of times.  A much cruder wood-engraved version of this map had illustrated an article on the “ Impolicy of Slavery ” in the Liverpool Mercury for October 31, 1823, followed by a reprint in The Kaleidoscope; Or, Literary and Scientific Mirror for June 29, 1824. The present map can be dated to 1825 or a bit later due to the presence of a “J. Whatman” watermark. Some may have been issued separately, but other impressions were folded and bound in to the Appendix of the Second Report of the Committee of the Society for the Mitigation and Gradual Abolition of Slavery throughout the British Dominions (London, 1825). Yet others were included in an untitled album of anti-slavery material published in 1827-28 by the Female Society, for Birmingham, West-Bromwich, Wednesbury, Walsall, and Their Respective Neighbourhoods, for the Relief of British Negro Slaves.

The abolition of the slave trade in the British Empire had occurred in 1807. However, it would not be until 1833 that slave ownership itself was outlawed.

The map is very rare: I find only examples at only six institutions and know of but one other having appeared on the market in recent years, offered by Crouch Rare Books in 2013.

Persuasive Cartography: The PJ Mode Collection, #1039.01. As of September 2017 OCLC lists holdings of the map at Boston Public Library (i.e., the Leventhal Map Center), Cornell, the Library of Congress and the University of Manchester Library. It also lists holdings of the Female Society’s untitled anti-slavery album, including the map, at John Carter Brown and the New York Historical Society.


Vertical folds, three small stains in the Pacific, and three round areas of discoloration at right edge (not affecting image), suggesting that at one point the map was tipped to an album or backing.