[Tokra]

You're sort of limiting your argument by selecting the Census reports from 1850-1860

Its the only one I could find. For Southerners to imply that slavery was as widespread in the North as it was in the South is absolutely preposterous.

[the OlLine Rebel]

No1 suggested it was "as widespread" - just that it existed. The point of the article was that NY was just as guilty as having slavery as any, and I guarantee you the impression we as kids got was that slavery was only a southern thing.

Conveniently by 1850, most "northern" states had banned slavery, so your point is moot.

As for it being as widespread - no, for 2 basic reasons I think:
a) the originating colonists' communities were inherently different in population density (= small land grants vs large) and attitude;
b) almost everything north of the M-D line is ROCK. There is hardly any good farming for the taking to make it a serious business North.

Basically, no big-business farms = fewer slaves.

But it doesn't erase the fact that northerners had slaves, something I guarantee we were not ever told in high school even.

[RavenATB]

I think you'll find that the reason that you only came across two census products that provided such information is that the US Census Bureau revised their counting criteria quite regularly in the mid 1800s...especially in regard to slaves.

Those who were rightly saying that slavery was not at all unusual in the north were not referring to the extremely limited time slot you've referred to with your pasted Census page, but to the last half of the 1700s, in which slavery was much less limited in geography.