In 1791, The United States Government admitted Vermont as the 14th state.
The original 13 colonies consisted of 14 colonies. Yet we do not have a 14th stripe on the flag. Vermont took itself out of joining the United States. Instead, they declared themselves an independent republic. Then in 1777, they created a constitution, the first national constitution and it prohibited slavery.
They kept their independence for 14 years. It could not have been easy. At one point they tried to have their independent republic rejoin the British Crown by joining Canada. Eventually, though, they petitioned to join the United States. When granted in 1791 Vermont joined as the 14th state.