Texas is the second-most populous state of the United States, with a population of over 28 million as of 2019. It is also the second-largest U.S. state by area and was admitted as the 28th state on December 29, 1845. Located in the south-central region of the country, Texas covers an area of 268,601 square miles and has many distinct regional climates. Texas is renowned for its oil and gas industries, cotton farming, and abundant wildlife. It is home to numerous rivers, including the Rio Grande, which forms the border with Mexico, and several major cities, including the state capital Austin and San Antonio, the most populous city in the state.