Yuma

Three centuries later, the advent of the shallow-draft steamboat made the settlement a point of entry for fortune seekers heading through the Gulf of California to mining sites in eastern Arizona. Fort Yuma was established in 1850 to guard against Indian attacks, and by 1873 the town was a county seat, a U.S. port of entry, and an army depot.

The steamboat shipping business, undermined by the completion of the Southern Pacific Railroad line in 1877, was finished off by the building of Laguna Dam in 1909. During World War II Yuma Proving Ground was used to train bomber pilots, and General Patton readied some of his desert war forces for battle at classified areas near the city. Many who served here during the war returned to Yuma to retire, and the city's economy now relies largely on tourism. The population swells during the winter months with retirees from cold climates who park their homes on wheels at one of the many RV communities. One fact may explain this: according to National Weather Service statistics, Yuma is the sunniest city in the United States.