Republic of Texas
The Republic of Texas was a sovereign country from 1836–1846.
The capital of Mexican Texas was San Antonio de Bexar. On 1835, it was provisionally San Felipe de Austin. The interim one on 1836 was Washington-on-the-Brazos, Harrisburg, Galveston, and/or Velasco. The capital was Columbia 1836–37. It was Houston from 1837–39. It was Austin from 1839–46.
The area was part of Spain until Mexican independence, then broke free shortly after. It had a border dispute with Mexico. Texas claimed territory extending to the Rio Grande, whereas Mexico claimed territory to a river further north. This was settled in Texas' favor following the Mexican-American War.