[Sloth]

A supposed constitutional right for a state to secede did not occur to people until the 1820s. It never even came up during the convention or ratification.

Probably because it was so obvious and self-evident that there was no reason to discuss it. For the Framers to secede from Britain but deny the right of secession to their own states would make them colossal hypocrites.

[arrogantsob]

The framers did not create the British government as they did the US government along with its mean to change itself.
They weren’t even allowed representation in Parliament.

On the other hand, the South controlled the federal government for most of the time between 1801 and 1860. It probably would have continued even longer had the Democrat Party not split into three parts for the 1860 election allowing Lincoln to win.