Missouri Compromise

Missouri Compromise (1820).In 1817, Missouri became the first territory within the boundaries of the Louisiana Purchase, apart from Louisiana itself, to apply for statehood. Subsequent congressional consideration of the issue led to the first major national debate between free and slave interests. Although the resulting compromise lasted for several decades, the dispute served as an omen of future sectional tensions, one that an aging Thomas Jefferson described with remarkable prescience as “a fireball in the night” and “a [death] knell for the Union.”

In February 1819, Congressman James Tallmadge of New York introduced an amendment to the Missouri statehood bill requiring that no further slaves be allowed into Missouri and that children of slaves already in the state (over ten thousand in 1820) be freed at age twenty‐five.

Tallmadge's amendment, coupled with a similar one banning slavery in the adjacent Arkansas Territory, sparked impassioned debate. The House of Representatives, on votes falling almost entirely along sectional lines, narrowly approved both amendments. The Senate, by a wider margin, rejected them and imposed no restrictions on slavery, present or future, in Missouri. When the next Congress convened in early December, Senator Jesse B. Thomas of Illinois proposed a compromise that, despite initial rejection in the House, passed in March 1820 when each provision was voted on separately. Under its terms, Maine, whose bid for statehood had been blocked by southern senators, was admitted as a free state; Missouri came in as a slave state; and, most significantly, Missouri's southern border, the 36°30′ parallel, was extended westward as the boundary north of which slavery would not be permitted within the Louisiana Purchase.

The significance of the Missouri controversy became fully apparent only in hindsight. It provided the impetus for the first full‐scale debate on what would emerge by midcentury as the central issue of the gathering sectional crisis: the territorial expansion of slavery. It also revealed the power of sectional interests to overwhelm partisan loyalties when this issue arose, and set a precedent for congressional authority in determining the limits and conditions of slavery's expansion. The Missouri Compromise defined the terms and the dynamics of a sectional crisis that would reemerge with even greater intensity in the later 1840s in the wake of the territorial gains resulting from the Mexican War.
See also Antebellum Era; Antislavery; Civil War: Causes; Compromise of 1850; Kansas‐Nebraska Act; Scott v. Sandford.

Bibliography

Glover Moore , The Missouri Controversy, 1819–1821, 1937.
William W. Freehling , The Road to Disunion: Secessionists at Bay, 1776–1854, 1990, chapter 8.

John C. Inscoe