I'd say Lincoln was pretty much more a libertarian in philosophy than anything else. I believe he was strongly against slave power. He was not like the Radical Republicans (who are really neocons and mainstream Republicans in today's era) who were imperialists looking to get Anglo-Saxon control. He was not like the Democrats either, who were also a racist party. I believe Lincoln was a sound man.
Well he definitely would not be a republican by today's standards, given how far downhill the party has come (ie Donald Trump), but I doubt he would be a democrat either (the democrats have also got pretty bad recently, and I highly doubt that the democrat party today is an exact copy of the republican party a century and a half ago). And libertarians are basically what the republican party is supposed to be (actually advocating for small government like republicans claim to do, except republicans mean they don't want to regulate businesses or protect the environment and then suddenly oppose personal freedom when it comes to gay people marrying or 18 year olds drinking beer). So Lincoln seems more like a libertarian (probably slightly left leaning on some issues and more right leaning on others but still mostly in the centre).
He said "In all that the people can individually do as well for themselves, government ought not to intervene." When Lincoln said "America will never be destroyed from the outside. If we falter and lose our freedoms, it will be because we destroyed ourselves." he was referring the liberal policies that attempt to enforce equality and the conservative social views that attempt to enforce traditional social order. Lincoln's presidency has provided the justification for the expansion of executive power, but this is an unfair justification. Lincoln was forced to declare martial law while in office because the country was in a state of internal CIVIL WAR and no president since has faced such dire times. Lincoln's main concerns were alway the freedoms of American citizens and he was willing to sacrifice order and equality to maintain them.
Lincoln personifies the Big Government, Big Taxes, powerful central government socialist. He transformed the Constitution by trampling over the States which created the federal government. James Madison said "the powers delegated to the general (federal) government are few and defined: the powers retained by the States are broad and numerous." The "free, independent and sovereign states" assigned a portion of their powers to address external issues like national defense and states limiting trade and interstate commerce. Lincoln fulfilled Hamilton's dream of strong central government and weak states.
From the time of the Founding Fathers and Framers to the Presidency of Abraham Lincoln, Laissez-faire proponents in the United States were not often portrayed as being fans of business. Jefferson, for example, believed firmly in the potential for limited government to help the farmer, not the business. People who wanted the free market to operate independently, the equivalent of libertarians today, would not have agreed with the core tenets of the Republican party. The Republicans, including Lincoln, believed in a protectionist economy, which runs contrary to the whole idea of libertarianism.