The Phoenix area first attracted settlers around 1 A.D., when a society of desert farmers called the Hohokam showed up in the Salt River Valley. No consensus exists on where the Hohokam came from, but there is little debate about their greatest legacy: 1,000 miles of hand-dug irrigation canals, many of which Phoenix still uses today. The Hohokam mysteriously vanished in the mid-1400s, perhaps due to drought, floods or warfare. When Spanish explorers galloped into the Southwest in 1539, they encountered a different group of inhabitants—the Akimel O’odham. This tribe claimed to be descended from the Hohokam and gave the ancient people their name, meaning “those who have gone.” Fast forward to 1865, when the U.S. government established Fort McDowell and settlers like Jack Swilling began farming the land. The city of Phoenix was formally established in 1868. Swilling’s friend, an Englishman named Darrell Duppa, suggested the name Phoenix in homage to the mythical bird that was reborn from ashes. Duppa’s suggestion saved the city from forever being known as Pumpkinville. By 1950, Phoenix had a population of about 100,000. Today, metro Phoenix is home to over 4 million people. The explanation for the population boom can be summed up in two words: air conditioning. When cooling units began popping up on rooftops and windowsills in the 1940s, the Arizona Republic declared Phoenix the “air-conditioned capital of the world.” By the mid-1950s, with refrigerated air reliably wafting through most of the city’s buildings, Phoenix’s population began to soar. Add in a steady influx of immigrants from the south, and a desert metropolis was born.