Lincoln did not suspend the Constition, just habeas corpus, which is perfectly constitutional.
Lincoln was a military tyrant, and used the Constitution as a doormat.
Nope. The Supreme Court, with Chief Justice Taney issuing an in-chambers decision, ruled that the President cannot suspend habeas corpus. Taney cited a plethora of historical/legal evidence supporting the decision.
For having the temerity to stand up to King Lincoln, Lincoln issued an arrest warrant to be served on Taney by Lamon - who refused to do so. Lamon once stated that Taney (not Lincoln) was one of the most outstanding men he'd ever met, and deserved his respect.
Lincoln suspended Habeas corpus without Congressional Approval which is unconstitutional.
Congress later retroactively approved it but that could be construed as an ex post facto law which is also unconstitutional.