Texas history is marked by its diverse cultural influences, including Native American tribes, Spanish explorers, and Mexican settlers. In 1836, Texas declared independence from Mexico, leading to the establishment of the Republic of Texas, which lasted until it joined the United States in 1845. The state played a significant role in the Civil War and experienced rapid growth during the 20th century due to industries like oil and agriculture. Key events include the Battle of the Alamo, the discovery of oil at Spindletop, and the rise of major cities like Houston and Dallas.