What it means
The Sun Belt is the warm southern third of the United States, Florida to California by way of Texas and Arizona, and the word stands for the great postwar migration that filled it. When an economist on local radio says the Valley is “a Sun Belt market,” she means a place that grows by importing people: retirees from Ohio, engineers from Illinois, Canadians for the winter. When a historian says Scottsdale is “a Sun Belt city,” he means something slightly less flattering: a city built almost entirely after 1950, around the automobile and the air conditioner, with a downtown that fits in a few blocks and a hundred square miles of subdivisions around it.
Both are right. Scottsdale had about 2,000 people on a single square mile when it incorporated in 1951. By the end of the 1960s it had nearly 68,000; by 1990 more than 130,000; by 2000 more than 202,000. The annexation guide explains how the city got the land, and this word explains why the people came.
Where you’ll meet it
Business pages, census stories and the mouths of real estate agents. Academic histories of Phoenix. The relocation guide, where the term explains why your neighbors are from somewhere else, and the history chapters on the 1950s and 1960s, where the migration arrives.
Where the word came from
Kevin Phillips was a 28-year-old Republican strategist when he published The Emerging Republican Majority in 1969, a thick book of maps and election returns arguing that the Democrats’ New Deal coalition was dying and that the party of Nixon would build a durable majority out of the booming suburbs of the South and West. He needed a name for the region whose growth was driving the shift, and he wrote “Sun Belt.” By one frequently repeated account he borrowed it from the Air Force, which had used the term for the favorable flying weather south of the Mason-Dixon Line; the claim appears in later commentary rather than in a documented source, so treat it as plausible rather than proven.
The word escaped the politics almost immediately. Through the early 1970s, as census figures showed population and jobs leaving the Northeast and Midwest, journalists adopted “Sun Belt” as shorthand for the winners. Kirkpatrick Sale’s 1975 book Power Shift described the same region as the “Southern Rim” and treated its rise as a threat rather than a promise; Phillips’s label won anyway, because it was friendlier and fit a headline. By the end of the decade “Sun Belt” versus “Rust Belt” was the standard frame for American economic geography, and it still is.
Scottsdale lived the thesis before it had a name. The 1950s brought Motorola’s research plant in 1950 and its McDowell Road expansion in 1956, the defense-electronics payroll every Sun Belt history cites. Air conditioning made the summers survivable for the engineers’ families. Winter visitors became retirees, and retirees became the base of the snowbird economy. The city’s professional council-manager government, adopted in 1961, was itself a Sun Belt fashion, the clean-government form that spread through the fast-growing cities of the Southwest after the war.
What it is not
The Sun Belt is not an official region and has no agreed border; it is a journalist’s and analyst’s label, and historians like Raymond Mohl have argued the growth it describes was national rather than regional. It is also not a synonym for the South. Phoenix shares the climate and the growth curve but little of the history, which is why Arizonans say “the Southwest” about themselves and “the Sun Belt” about their economy.
The fine print
Geographers who want a line usually draw it at 36 degrees 30 minutes north latitude, the old Missouri Compromise line, which sweeps in Arizona, New Mexico, Texas, Florida, the Gulf states and South Carolina and clips the southern parts of California, Nevada, Utah, Oklahoma, Arkansas, Tennessee and North Carolina. Five of those states, Arizona, California, Florida, Nevada and Texas, acquired a second nickname after the 2008 housing crash, the “Sand States,” for their beaches, deserts and foreclosures.
The engines of the migration are well documented and all of them ran through Scottsdale. Federal defense spending built the aerospace and electronics plants, Motorola’s among them. Low union membership and boosterish local governments drew employers; Scottsdale’s own Chamber of Commerce organized in 1947 to do exactly that. Air conditioning, generally available in homes from the 1950s, made the summers tolerable, and the earlier swamp cooler had made them survivable. Warm winters drew retirees and the resort trade, which here predated the term by decades in the form of the health seekers and dude-ranch guests of the 1920s and 1930s.
The migration has not stopped. Census tabulations of the fastest-growing ZIP codes since the pandemic put most of them in Texas, Florida and Arizona, and the Phoenix metro passed 5 million people in the 2020s. What has changed is the politics Phillips predicted: the suburban Sun Belt he expected to anchor a permanent Republican majority has become, in Arizona as in Georgia, the most closely contested ground in the country, which is the irony every later writer on the subject gets to point out.