Sun Belt or Sunbelt, southern tier of the United States, focused on Florida, Texas, Arizona, and California, and extending as far north as Virginia. The term gained wide use in the 1970s, when the economic and political impact of the nation's overall shift in population to the south and west became conspicuous. Areas near the Mexican border have received millions of immigrants since the 1960s. Economic growth in many Sun Belt cities since World War II has stimulated interregional migration from the NE United States and the Rust Belt; by 1990, Los Angeles, San Diego, Phoenix, Houston, Dallas, and San Antonio were among the ten largest cities in the United States. During the 1990s the fastest growing cities in the United States were in the Sun Belt. The warm climate has attracted large retirement communities, especially in Florida and Arizona. In addition, the birth rate in the Sun Belt is about 10% greater than that in the rest of the country. Attracted by the relative lack of labor unions and the prospect of cheaper labor than was generally available in the north, manufacturers began to locate in the Southeast in significant numbers after World War II; aerospace firms and defense contractors were drawn to the vicinity of military bases in S California and throughout the Southwest. Texas, Louisiana, and Oklahoma benefited from the oil booms of the 1970s. In addition, the enormous tourist industries of the Sun Belt (especially Florida and S California) have brought the region considerable wealth. Although overall the expansion of the Sun Belt's economy in recent decades has been dramatic, the distribution of the region's prosperity has been uneven; of the 25 metropolitan areas with the lowest per capita income in 1990, 23 were in the Sun Belt. The rapid fall of oil prices in the 1980s hurt the economies of the energy-producing areas of the Sun Belt; Houston was especially hard hit. By the 1980s, the Los Angeles area, beset by problems ranging from air pollution to a growing population of unskilled immigrants, came increasingly to resemble some of the troubled metropolitan areas of the North. Politically, the rise of the Sun Belt has generally been viewed as advantageous to the Republican party, especially in presidential elections. Since 1970, the Sun Belt has gained more than 25 electoral votes, mostly at the expense of the Northeast and Midwest.
See B. L. Weinstein and R. E. Firestine, Regional Growth and Decline in the United States: The Rise of the Sunbelt and the Decline of the Northeast (1978); C. Abbott, The New Urban America (1987); R. M. Miller and G. E. Pozzetta, ed., Shades of the Sunbelt: Essays on Ethnicity, Race, and the Urban South (1988); R. A. Mohl, ed., Searching for the Sunbelt (1990).