The Articles of Confederation and Perpetual Union described:
https://www.history.com/topics/early-us/articles-of-confederation
The founders rejected the requirements of the Articles of Confederation when they created the US Constitution.
A most important requirement of the Articles of Confederation was unanimous consent. The government was not allowed to do anything without the approval of *ALL* states.
When they created the US Constitution, they failed to get approval from all the states, and were therefore violating the Articles of Confederation, making them defunct.
They also never added "perpetual" to the "Union" described by the Constitution.
Virginia, New York and Rhode Island stipulated in their ratification statements that they had the right to take back their powers from the Central government if they ever decided the Central government was infringing upon the rights of the people of their states.
Perpetual Union is in the Articles, not the Constitution.
When George Washington was inaugurated President on April 30, 1789 there were only 11 States in the Union and not the 13 under the Articles.
NC and Rhode Island were outside of the new union.
North Carolina didn’t become the 12th State until November 12, 1789. Rhode Island didn’t become the 13th State until May 29, 1790.
Lincoln ignored that history and claimed that perpetual union was part of the Constitution in order to justify using military force against seceding States.