Industries such as aerospace, defense, and oil boomed in the Sun Belt as companies took advantage of the low involvement of labor unions in the region (due to more recent industrialization, 1930s–1950s) and the proximity of military installations that were major consumers of their products. The oil industry helped propel states such as Texas and Louisiana forward, and tourism grew in Florida and Southern California. More recently, high tech and new economy industries have been major drivers of growth in California, Florida, Texas, and other parts of the Sun Belt. Texas and California rank among the top five states in the nation with the most Fortune 500 companies.