In this unusual work Marshall Hall (1790-1857), an English physician who had undertaken at 15-month journey in America, argues that for demographic, economic, moral reasons the emancipation of slaves is a necessity rather than a choice. This imperative is complicated, however, by the fact that the United States suffered from a “two-fold slavery:” the first being the enslavement of millions of blacks; the second, and more pernicious in his view, being the “prejudice” and “oppression” suffered by free blacks:
“In effect, the African in the slavery of the United States is so well cared for, he is for the most part, according to the expression of Henry Clay, ‘fat and sleek,’[!] and his numbers increase in a higher ratio than those of the European ; whilst the African said to be free is so crushed by State legislation and popular prejudice and oppression as to provide for himself and family through extreme difficulties, and is at once wretched individually and scarcely increased his numbers as a race… (p. 2)
Hall therefore rejects abolition as misguided, given the systematic oppression suffered by free blacks, as well as being unjust[!] to slave owners. He also rejects colonization as impractical given the size of the black population and the importance of its labor to the American economy.
He proposes instead a system of “self-emancipation.” On this model, slaves would be given the opportunity to work overtime[!] for pay, bank their wages, and use the savings—boosted by state and/or Federal subsidies—to purchase their freedom. At the same time they would be educated and otherwise prepared for life in the free world. “The object of this suggestion is, not that of immediate and total emancipation…. it is that of a self, yet aided, emancipation ; gradual, progressive, and finally complete ; combined with the simultaneous discipline and elevation of the African race.” (p. 61) As history demonstrates, these recommendations did not gain a lot of traction.
Hall’s work includes two “chloropleth” maps, in which areas are shaded in proportion to the measurement of some statistical variable. The first is a “Map of Slavery in the United States,” in which the intensity of shading “represents the degree of Slavery in the Several States” (“Degree,” in this case, appears to be a simple measure of the absolute number of slaves in a given state.)
On the second map the shading “represents the degree of Unfriendliness of the European to the African Race.” The metric used to determine the level of “unfriendliness” is the proportion of free blacks to the white population, which yields some extremely odd results. Georgia, Alabama and Mississippi are, not surprisingly, “unfriendly,” with ratios of 1:180, 1:194 and 1:328 respectively… but the prize for racial hostility apparently goes to Maine (1:447.5), Vermont (1:447.7) and New Hampshire (1:634.4)! (“I trust, the unfriendliness of the last three is more that of climate, than of the people.” –p. 122) By contrast, the friendliest states to blacks are Maryland (1:5.6) and Deep-South Louisiana (1:14.6).
The 1850s saw the publication numerous persuasive maps that used color or shading simply to differentiate free and slave states. However, Hall’s two maps represent to my knowledge the first attempts to depict demographic data about American slavery on a map, as well as the first attempts at applying the chloroplethic technique to any American subject. At the outset of the Civil War this would of course be done, and with far more sophistication, by Edwin Hergesheimer of the United States Coast Survey.
OCLC lists numerous institutional holdings of Two Fold Slavery, but the volume is very rare on the market. I find none offered for sale at present, and according to Rare Book Hub the last copy to appear on the market was offered by MS Rare Books in 1979.
Sabin #29825. Not in Persuasive Maps: The PJ Mode Collection.
Cloth faded and a bit soiled, hinges somewhat tender, minor creasing and foxing to maps.