There was specific constitutional provision for emergency measures in the case that Abraham Lincoln faced - an insurrection - which no other president has faced.

I am asked often about Abraham Lincoln's mistakes and faults; he certainly made some mistakes. I have chapter in President Lincoln about the Powhatan affair that was a royal screw-up in the early days - right alongside the Sumter affair. Lincoln signed letters he should not signed, and the ship was sent to two places at one under two captains etc. Fortunately, no great harm. Lincoln took the blame and did not do anything like that again.

All presidents - particularly war presidents, presidents inclined to the imperial presidency - invoke Abraham Lincoln as a justification, but they omit these three defenses of Lincoln's strong actions. Suspend habeas, blockade, increase army without congress, arrest Maryland legislators, etc.

Abraham Lincoln did not contend that his actions were immune from Congressional correction; on the contrary, he specifically said he was acting beyond the present provisions in the expectation that congress would retroactively approve, which they did. He did not say anything like Richard Nixon: if the president does it is legal.

Abraham Lincoln was not philosopher, exactly. But he did have a strong mind, which sought generalizations as well as particulars. He had a terrific memory.

Abraham Lincoln had great clarity of mind and expression, and he worked to make it clearer -reading Euclid in his early 30s to train his mind.

Abraham Lincoln had a deep realism; he did not deceive or mislead himself, but faced the world he had to deal with as it really is. At the same time, he had a striking moral intelligence, and a confidence in the working of his own mind and conscience.