[Steve Van Doorn]

It was Abraham Lincoln that sponsored the Corwin Amendment. If the Southern states had voted it would've passed as the 14th amendment. Corwin Amendment would've allowed slavery in the US.
https://en.wikipedia.org/wiki/Corwin_Amendment

[rockrr]

It was Abraham Lincoln that sponsored the Corwin Amendment.

I think you mean President Buchanan.

[Bull Snipe]

That would have been the 13th Amendment, not the 14th.

“The Amendment would not have allowed slavery in the United States.”

The Constitution already allowed slavery in the United States. What the Corwin Amendment would have done is to prevent the Federal Government from initiating any action (such as a Constitutional Amendment) to interfere with any domestic institution (slavery).