The United States and Texas34. 5 by 30 inches framed. This outstanding map includes a wealth of information on both the independent Republic of Texas as well as the 26 States Back East. The Western border of Texas had been established by treaty as the Rio Grande River to its source. as recorded on this map. In the lower left corner of this map is this important notation: The Independence of Texas was formally declared in March 1836. It was recognized by Great Britain in