Illustrating an impolicy

TitleChart of the World, on Mercator’s Projection: Illustrative of the Impolicy of Slavery
CreatorJames Cropper
Year[ca. 1825]
Dimensions11 × 19 cm
LocationLeventhal Map & Education Center at the Boston Public Library
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The yellow lines on this map highlight the 30 degree mark on either side of the equator, showing the extent of areas that can produce sugar. Theoretically, any land between these areas could be suitable for sugar cultivation, based purely on the plant’s theoretical growing range—though of course places like the Sahara Desert and the Australian Outback would never be filled with sugar fields. But by showing a huge section of the globe as the potential agricultural territory for sugar, the author of this map, the abolitionist James Cropper, could draw an exaggerated comparison to the tiny red dots in the Caribbean and South America where British slave colonies produced the bulk of the empire’s sugar.

This map, therefore, is trying to make an economic case against slavery. Cropper argues that opening the sugar trade to the rest of the world would lead to an economic explosion which “would give employment to the destitute population of Ireland and Great Britain.” The geographic and economic argument here is extremely strained—it’s unlikely that most of Britain’s poverty could be attributed to protective trade regimes that privileged the slave colonies—but it nevertheless became one of the cases put forth by British reformers who favored abolition. As it happens, Britain began freeing its slaves far earlier than the United States, and the passage of the Slavery Abolition Act of 1833 less than a decade after this map was published was a major turning point in the British use of slave labor, both in sugar cultivation and elsewhere.