The 13th Amendment we know now differs substantially from the one first proposed. The initial amendment would have made slavery constitutional and permanent — and Lincoln supported it.

This early version of the 13th Amendment, known as the Corwin Amendment, was proposed in December 1860 by William Seward, a senator from New York who would later join Lincoln’s cabinet as his first secretary of state.

The Corwin Amendment read as follows:

No amendment shall be made to the Constitution which will authorize or give to Congress power to abolish or interfere, within any State, with the domestic institutions thereof, including that of persons held to labor or service by the laws of said State.

The Corwin Amendment was an effort to placate the South and contain secessionist sentiment. It proposed to do three things. First, to protect slavery by giving each state the power to regulate the “domestic institutions” within its borders. This was an enticing carrot for the slave states: stay in the Union and you can keep slavery. Second, to dispossess Congress of the power to “abolish or interfere” with slavery. And third, to make itself unamendable by providing that “no amendment shall be made to the Constitution” that would undo the Corwin Amendment.

After Seward proposed the Corwin Amendment, then newly-elected President Lincoln defended the states’ right to adopt it. In his first inaugural address Lincoln declared that he had “no objection” to the Corwin Amendment, nor that it be made forever unamendable.

Read More: The ‘Ghost Amendment’ That Haunts Lincoln’s Legacy | Cognoscenti