|Texas is the second largest state in the United States in area as well as in population. It has an area of 268,820 square miles with a length of 790 miles and a width of 773 miles. The population was 24,326,974, as estimated in 2008 with a density of 79.6 per square mile. Located in the south central region of the nation, Texas is bounded by Louisiana and Arkansas on the east, Oklahoma on the north and the Mexican states of Coahuila, Chihuahua, Leon, Nuevo and Tamaulipas to the south. The Rio Grande, Sabine and Red River are some of the most important rivers, which also form natural borders of the state. The territory of Texas was under Mexican rule until 1836 when it became an independent Republic. Later in 1845, it joined the USA as the 28th state of the country. The state is a home of the some of the largest cities in the US. Houston, which is the largest in the state, ranks fourth among the largest cities of the nation. Dallas-Fort Worth, on the other hand, is the largest metropolitan area in the state and also the fourth-largest in the country. Austin is the capital while San Antonio and El Paso are other major cities in Texas.