Your ignorance is astounding. The Confederates seceded because they opposed a Constitution that permitted the abolition of white supremacy and their cherished institution. Here's how Confederate Vice President Alexander Stephens put it when explaining why he thought the signers of the Declaration of Independence were wrong if they meant to include Negroes among `all men':
"Our new government is founded upon exactly the opposite idea; its foundations are laid, its cornerstone rests, upon the great truth that the negro is not equal to the white man; that slavery ... is his natural and normal condition. This, our new government, is the first in history of the world based upon this great physical, philosophical, and moral truth."
Bringing it up is simply a means of covering your backside when logic and a clear reading of the document in question has sent you Unlimited Government Supporters scurrying for cover.
As a responsible libertarian, I'm hardly a supporter of "unlimited government", but you're not going to promote liberty by distorting history and demonizing the man who was largely responsible for the most libertarian provision in the U.S. Constitution (i.e. the 13th Amendment). If anyone in the Civil War era is responsible for promoting a big federal government it is the Confederates, who demonstrated quite adeptly how tyrannical state governments can be.
If you still think that Lincoln put America on the path of big central government, take a look at this revealing chart:
Real Per Capita Expenditures: 1800-1990 (In Constant 1990 Dollars)
Source.
Note how federal government outlays dropped drastically after the Civil War and stayed very low for many decades thereafter. The explosive growth of the federal government is a 20th Century phenomenon. It is obscenely preposterous to blame Abraham Lincoln for what happened 65 years after he was murdered by a Confederate sympathizer.
the Constitution places limits on what can be done to the citizens and in their name.
Not really. The Constitution is so ambiguous and contradictory that it can be used to support practically any agenda if the Supreme Court approves. What really places limits on tyranny is human will to resist it. It was not the Constitution that abolished slavery, it was the wiil of the Union soldiers to oppose the insidiuos slaveholder mentality of the Confederates.
You may be passionate about your Yankee heritage, but your ancestors trampled the U.S. Constitution, and doing so has led us to this point.
Yes, I'm sure that you'd much prefer that those damned Yankees had been as cowardly as the Confederates assumed they were and just looked the other way when the Confederates you glorify kept Negro men, women, and children underfoot with whips and chains.
... for only 15% of Southerners owned slaves...
Actually, about 1/3 of Southern families owned slaves, and the slaveholders conned most of the nonslaveholding Southerners into supporting the Confederacy by extolling the benefits to them of white supremacy and frightening them with the prospect of free black men raping or marrying their daughters.
All of your ancestors fought to partially free the Black slaves, but in doing so made slaves of us all!
Even with taxes eating up 50% of our incomes, that's a far cry from slavery, and blaming Civil War era people for what happened in the 20th and 21st Centuries is ridiculous. Moreover, were the 13th Amendment's prohibition of "involuntary servitude" to be literally enforced, there would be no taxation. You can't blame Abe Lincoln for the Supreme Court justices who refuse to follow the key Constitutional Amendments he pushed through. (As a matter of fact, Lincoln appointee Stephen J. Fields was arguably the most libertarian Supreme Court Justice of all time and was very instrumental in keeping tyranny at bay during his long court by citing the 13th and 14th Amendments).
You do the tree of liberty little service by hacking away at its healthier branches.