Missouri Compromise of 1819: Missouri Seeks Statehood as a Slave State

The United States in 1819. The Missouri Compromise prohibited slavery in the unorganized territory of the Great Plains (upper dark green) and permitted it in Missouri (yellow) and the Arkansas Territory (lower blue area).

Missouri proposes to enter the Union as a slave state, instigating the Missouri Compromise. Maine enters the Union as a free state.

Missourians To Be Denied New Slaves

In 1819, a bill was presented in the House of Representatives, authorizing Missouri to draw up a constitution for statehood. Since slavery was already lawful in the territory it was assumed that Missouri would enter the Union as a slave state. However, James Tallmadge of New York introduced an amendment to this bill. Tallmadge moved that after Missouri became a state no more slaves could be brought into the new state. He also included that all children who were born of slaves in Missouri after she became a state would receive their freedom at the age of 25.

Debate on Slavery Rages

Although free-state members approved Tallmadge’s proposal representatives from the Southern states were dramatically alarmed at both of these proposals. After three days of debate on these proposals the House passed the amendment. But the passing of these amendments did not halt the raging debate throughout the country.

Up until this time there had been a balance between slave states and free states, there being 11 of each. If Missouri was made a state, and allowed to remain a slave state, this delicate balance would be upset. It would also shift the balance of power to the South.

Although the House passed Tallmadge’s amendments, the Senate rejected them, leaving Missouri to continue in its effort to become a state.

No New Slave States in the Territory

The next Congress, however, agreed to a compromise. Maine was now seeking admission as a free state. Senator Jesse B. Thomas of Illinois proposed that, with the exception of Missouri, new slave states should not be made out of the territory included in the Louisiana Purchase “north of 36o30″ N. latitude, the contemplated southern boundary of Missouri.”

Both the House and the Senate agreed to let Maine and Missouri enter the Union. Missouri would be a slave state and Maine would be a free state. But the upheaval was far from over.

No Free Blacks in Missouri

Several months later a supplementary Missouri Compromise had to be made. The Missourians had prepared a constitution, forbidding the state legislature to pass a law freeing slaves without the consent of their masters. The state legislature had also passed a law prohibiting the entrance of free black people into the state. The national House promptly voted against the admission of Missouri under this proposed constitution. Another compromise was arranged, mainly through the efforts of Henry Clay.

Missouri a Slave State, Main a Free State

Missouri was finally made a state on the condition that “its legislature pledge never to ignore the rights of citizens of another state coming to Missouri.” Missouri became the 24th state on Aug. 10, 1821. Main, the 23rd state, had already been admitted nearly five months earlier.


  1. Comptons, The Complete Reference Collection. CD Rom, 1997, The Learning Company, Inc.
  2. Montgomery, D. H. The Leading Facts of American History. Ginn and Company, Boston and New York, 1890.