Recently, I speculated on why Abraham Lincoln had signed the 13th Amendment, and asked whether anyone knew the actual reason why. Seth Barrett Tillman writes in to suggest another possibility:
that Lincoln was unaware of the Supreme Court’s opinion (such as it was) in Hollingworth v Virginia [which appeared to hold that presentment to the President was unnecessary in the case of constitutional amendments]. Prior to the 13th Amendment, it had been half a century since a proposed amendment was passed by Congress and ratified by the States. It may simply have been that Lincoln had no idea what the regular time-honored procedure was and simply assumed it required his signing. This view would have been strengthened by the fact that Buchanan had signed the proposed Corwin Amendment.
One of Lincoln’s contemporaries — part of the congressional committee which delivered the proposed amendment to Lincoln — was of the view that Lincoln had to sign it. Afterwards, the Senate had a debate on the propriety of Lincoln’s actions and its precedential value. As I remember (from reading the debates some years ago), the Senator was surprised to learn that prior practice from the Bill of Rights and the 11th and 12th Amendments did not involve presidential signatures. My point is that the Senator made an honest mistake in regard to prior practice. It is possible that Lincoln did so too.
This is quite interesting and sounds very plausible. Seth has more about Hollingsworth here.