Missouri Compromise is adopted in Washington, D.C.

Passed by Congress, the law admits Maine into the Union as a separate state from Massachusetts and a free state and admits Missouri as a slave state. It also prohibits slavery, which John Quincy Adams denounces at the time as “the great and foul stain upon the North American Union, north of the 36 degree, 30 minutes latitude. Both Massachusetts senators vote in favor of the legislation.