I'm not a big fan of Lincoln. I tend to side instead with Lysander Spooner, who was both a radical abolitionist and a confederate sympathizer. He argued that the right of southern states to secede derives from the right of slaves to be free, and that they were justified in waging war for their freedom just as slaves were right to kill their masters. Needless to say, neither side liked him very much.
He was the favorite choice of running mate for Lincoln's primary election opponent General McClellan, but turned it down because he considered the Republican party to be a corrupt organization beholden to big business.
Lincoln was the most pro-big business and pro-big government president that had been elected at the time. Like all republicans at the time he was for high protective tariffs. This was before the party even began to pretend to be for a laissez-faire free market. Much of Lincoln's work before being elected president was focused on granting massive subsidies to the robber barons who ran the rail road industry and protecting them from having to return any of their land grants or submit to public regulation.
Lincoln introduced the first income tax, which was patently unconstitutional at the time. His unbacked paper currency was also ruled unconstitutional. While the constitution does allow the suspension of the privilege of the writ of habeas corpus during the event of rebellion or invasion, it does not permit the full scale martial law he put into place in states he feared were about to secede.
One of Lincoln's first acts as president was supporting a constitutional amendment that would have guaranteed the continuation of slavery where it then existed. (He signed this amendment, even though such a signature was legally meaningless. Some claim that it was an attempt to overwrite the earlier 13th (Titles of Nobility) Amendment, as his membership in a bar association granting the title of esquire would have cost his his citizenship and eligibility for public office. Of course, it is unclear is esquire counted as a title of nobility, and most of the evidence points to the previous 13th amendment not having ever really been passed since new states were added just barely fast enough to prevent it from gaining a supermajority.) He was quite clear that he had no intention to act on his personal opinions opposing slavery. His focus was on forcing the country to stay together.
The way he sent troops to South Carolina to provoke the confederacy to start the war seems oddly hypocritical coming from the man who issued the spot resolutions and denounced the president who started the Mexican-American War by sending troops to the disputed territory in Texas/Mexico.
I'm not exactly sure how credible his partner from his law firm was, but if he is to be believed Lincoln was not a particularly good man. In addition to maligning his as an incompetent and corrupt lawyer who desired only to further his political ambitions, he spoke of many other vices like Lincoln frequenting prostitutes. (Allegations of him being gay did not emerge until much later and are almost certainly baseless.)