The history of the 13th Amendment is very long, but here is the summarized history from Wikipedia. And I quote, "During the secession crisis, the majority of slavery-related bills had protected slavery. The United States had officially ceased slave
importation in 1807 after the Act Prohibiting
Importation of Slaves and the British Slave Trade Act 1807 It had
intervened militarily against the Atlantic slave trade and had made few
proposals to abolish domestic slavery, and only a small number to abolish the
domestic slave trade. Representative John Quincy Adams had made such a
proposal in 1839, but there were no new proposals until December 14, 1863, when
a bill to support an amendment to abolish slavery throughout the entire United
States was introduced by Representative James Mitchell
Ashley (Republican, Ohio). This was soon followed by a similar proposal made by
Representative James F. Wilson (Republican, Iowa).Eventually the Congress and the public began to take notice, and a number of additional legislative proposals were brought forward. On January 11, 1864, Senator John B. Henderson of Missouri submitted a joint resolution for a constitutional amendment abolishing slavery. The abolition of slavery had historically been associated with Republicans, but Henderson was one of the War Democrats. The Senate Judiciary Committee, chaired by Lyman Trumbull (Republican, Illinois), became involved in merging different proposals for an amendment. On February 8 of that year, another Republican, Senator Charles Sumner (Radical Republican, Massachusetts), submitted a constitutional amendment to abolish slavery as well as guarantee equality. As the number of proposals and the extent of their scope began to grow, the Senate Judiciary Committee presented the Senate with an amendment proposal that combined the drafts of Ashley, Wilson and Henderson.The Senate passed the amendment on April 8, 1864, by a vote of 38 to 6. However, just over two months later on June 15, the House failed to get the necessary two-thirds vote for passage, with 93 in favor and 65 against. Representative Ashley was instrumental in its eventual passage. An ardent Free Soiler before becoming a Republican, he was the House floor manager and persuaded a number of Democrats to support it. President Lincoln took an active role in working for its passage through the House by ensuring the amendment was added to the Republican Party platform for the 1864 presidential election and using his powers adroitly. Finally, after seven months of debate and promises of patronage, the House narrowly reached the two-thirds majority needed to pass the bill on January 31, 1865, by a vote of 119 to 56. The Thirteenth Amendment's archival copy bears an apparent Presidential signature, under the usual ones of the Speaker of the House and the President of the Senate, after the words "Approved February 1, 1865"."