Three U.S. States That Were Independent Countries

1. Texas – Republic of Texas (1836–1845), annexed via joint resolution.
2. Hawaii – Kingdom of Hawaii (1795–1893), Republic of Hawaii (1894–1898), annexed by Newlands Resolution.
3. Vermont – Vermont Republic (1777–1791), admitted as 14th state.

Each had its own constitution, government, and diplomatic relations before joining the Union.