Missed that whole 13th Amendment thing in 1864-65 did you?
Yeah, he also missed the District of Columbia Compensated Emancipation Act of 1862....but blunders like that are common for him, being such a cartoonish character.
What effect did the proposed 13th Amendment have during the Civil War and what effect did it have for slaves in Union states after the conclusion of the war? None, not until passage. Why didn't the virtuous Union pass the 13th Amendment itself? They were afraid to upset the Union slave states.
What role did the army play in that? Because sauce for the goose ought to be sauce for the gander.