Dividing the Union: Jesse Burgess Thomas and the Making of the Missouri Compromise by Matthew W. Hall (review)

When the average student of early-nineteenth-century America recalls the great political leaders of that era, Senator Jesse B. Thomas of Illinois does not immediately spring to mind. That able—if unassuming—legislator, best known for proposing the Missouri Compromise's 36°30' line of demarcation between slave and free territory, is generally mentioned in passing while titans such as Henry Clay occupy center stage. In Dividing the Union, Mathew W. Hall has endeavored to give Thomas his due, utilizing the narrative of his subject's successive migrations and his progress up the political ladder as a lens through which to understand the issue of slavery in the early republic.

Born in Maryland in 1775, Jesse Thomas moved with his brothers repeatedly westward in search of an appropriate arena for their talents. They settled for a time in Pennsylvania, then Ohio, Kentucky, and eventually the Indiana Territory. Jesse initially became a protégé of Governor William Henry Harrison, but the two had a falling out when Harrison supported another candidate for the post of delegate to Congress in 1808. Thomas nonetheless won election to the position and served a brief stint in Washington. There he found a new mentor in influential Georgia senator William Crawford. At the end of his term, in March 1809, Thomas moved west yet again to take up the post of federal judge in the newly created Illinois Territory.

Hall reminds the reader that the lines between slave and free territory were not always as clear in the Trans-Appalachian West as they would appear in retrospect. He offers analysis not only of the well-known clause (Article VI) of the 1787 Northwest Ordinance that banned further importation of slaves north of the Ohio River but of a similar restriction in Thomas Jefferson's proposed 1784 ordinance, never adopted by Congress, that might have placed slavery on the road to extinction throughout the West. Hall emphasizes that prior to the 1830s the antislavery language of both the Northwest Ordinance and subsequent state constitutions was most often honored in the breach, especially in those parts of Ohio, Indiana, and Illinois settled by immigrants from the slaveholding southern states. Thomas, like many other prominent Illinoisans at the time of statehood, in 1818, owned slaves whom he euphemistically identified as "indentured servants." Indeed, even for some time after settlement of the Missouri controversy, the free status of the lands north of the Ohio was by no means a sure thing.

This becomes clear in Hall's explanation of the 1818 Illinois constitutional convention, where Thomas served as the presiding officer. The delegates only narrowly rejected an article openly allowing slavery, deciding instead to incorporate language that banned the introduction of new slaves into Illinois, kept those already there enslaved under the fig leaf of a "contract" system, but freed the male and female children of bondsmen upon reaching adulthood. Thomas and his allies adopted language sufficiently ambiguous to be accepted by Congress while leaving the door open to explicitly proslavery revision by 1823. "Illinois," says Hall, "thus bided its time, delaying for five years the attempt to establish slavery in the new state. … This contrasted dramatically with the more confrontational and incendiary approach taken by Missouri's constitutional convention in 1820" (99).

Selected to represent Illinois in the U.S. Senate, Thomas took his seat in the Fifteenth Congress just as the crisis brought on by Missouri's petition to enter the Union as a slave state and New York representative James Tallmadge's proposal to restrict slavery broke upon the national scene. For much of the second half of Dividing the Union, Thomas remains in the background while Hall relates the details of the congressional struggle to find a resolution acceptable to all parties. Only when the action shifts to the upper house does Thomas again become a key figure. To garner northern support...