Your knowledge of history is sorely lacking. 7 of the original 13 were free states. New York, Pennsylvania, Connecticut, Massachusetts, New Hampshire, New Jersey and Rhode Island.
New York did not free the last slave until 1827. They didn't even *START* freeing slaves until 1799.
Pennsylvania still had slaves as late as 1840.
Connecticut went till 1848 before it had eliminated slavery.
Massachusetts outlawed it by Judicial decree in 1781 which I already mentioned, but it was not officially abolished until the 13th amendment in 1865.
New Hampshire had slavery until 1857.
New Jersey had slavery until 1846.
Rhode Island had slaves on the census until 1840.
So my point stands. At the time the US Constitution was written, the vast majority of all Northern states were still slave states.
Deleware was the only exception in what were considered the Northern Colonies. The slave states were the ones that sided with the South in the Civil War with one exception...Maryland.
Please. You tell me *my* history is bad, and you say stuff like that? Missouri was a Union state that had legal Slavery. So was Kentucky. So was West Virginia. As for Maryland, when you arrest members of the legislature who might have voted to secede, you can effectively stop a secession in that state.
An oddity of history is that Slavery existed longer in the Union than it did in the confederacy.
So your theory about something that was in your words "prevalent" is blatantly false. The majority of the original 13 were indeed free states.
Okay, here is where you need to go back and do some research and learn the truth, then come back and argue with me about it.