Austin is the capital city of the U.S. state of Texas, as well as the seat and largest city of Travis County, with portions extending into Hays and Williamson counties. Incorporated on December 27, 1839, it is the 11th-most-populous city in the United States, the fourth-most-populous city in Texas, the second-most-populous state capital city, and the most populous state capital that is not also the most populous city in its state. As of 2021, Austin had an estimated population of 964,177,[3] up from 961,855 at the 2020 census