Cotton, cattle, and crude (oil)—Texas’s venerable “Three Cs” dominated the state’s agricultural and economic development until the mid-20th century, and these land-based resources continue to support much of the state’s wealth. Other factors contributing to Texas’s economy are various industries not exclusive to the Lone Star State, such as retailing, wholesaling, banking, insurance, and construction.
Many national corporate headquarters have relocated to Texas (especially to the midcontinental location of Dallas ), and petroleum companies continue to search for new sources of energy to provide fuel. In addition, Houston  is home to many federal air installations and NASA’s prestigious Lyndon B. Johnson Space Center, while Austin  is home to Dell Computers and other esteemed high-tech companies. Tourism has also become a major business, particularly in San Antonio , and Texas has become a leader in the areas of medicine and surgery.