During 1819 the question was discussed throughout the Union. Several legislatures, by unanimous votes, protested against admitting a new Slave State, and when the new Congress assembled in 1819 it became the principal issue of the session. Alabama was at once admitted, restoring the balance of Slave and Free States. The people of Maine were now about to separate from Massachusetts, and also petitioned for entrance into the Union. A bill for this purpose passed the House on December 30, and a month later a bill for the admission of Missouri, with the Talmadge amendment, was also introduced into the House. The Senate, on Feb. 16, 1820, voted to admit Maine, provided Missouri was at the same time admitted as a Slave State. The House still refused to comply. Thomas of Illinois now proposed as a compromise the principle suggested by McLane a year earlier,--that an east and west line be drawn across the Louisiana cession, north of which slavery should be prohibited. Fourteen Northern members united with the seventy-six Southern members to form a bare majority against prohibiting slavery in Missouri; the principle was thus abandoned, and the only question was where the line should be drawn: the parallel of 36° 30' was selected, but it was expressly provided that Missouri should be slaveholding. On March 3 the compromise became a law. [Sidenote: Missouri constitution.] A year later a third difficulty arose. The people of Missouri had formed a constitution which provided that free colored men should not be allowed to enter the State under any pretext. Nearly the whole Northern vote in the House was cast against admitting the State with this provision. Clay brought about a compromise by which the Missourians were to agree not to deprive of his rights any citizen of another State. Upon this understanding Missouri was finally admitted. [Sidenote: Friends of disunion.] [Sidenote: Advantage to the South.] [Sidenote: Advantage to the North.]