Lincoln is the worst president in history. Despite not caring about black people at all, and the fact that the Confederacy was killing itself economically anyway, the only reason Lincoln wanted the Civil War was to unite the nation and not allow the South to secede. The Constitution IS an agreement, and the South disagreed with it on several levels and had every right to secede. Had Lincoln not been such a violent, warmongering totalitarian, and worked out an economic way to end slavery, and leave the Confederacy alone, I'd have no problems with him. The industrial revolution destroyed the need for slaves as machinery, overall, was a far better investment and never got tired or rebelled. Instead, Lincoln forced the South into an open war and many slaves were killed in the process there of and ended up WILLINGLY fighting the North. I disagree with the South's reasons for seceding (slavery being a key issue) but I do not disagree with their right to secede.
As for presidents - I think any since Lincoln were horrible with a few that did nothing important being less horrible. FDR basically created the economic position we are in with the "New Deal". We have had a string of REALLY bad presidents recently with Reagan (who veered off his right slant economically once being elected), Bush Sr, Clinton, and Bush Jr. Essentially starting with Lincoln every president has been worse than the one before him.