The Phoenix metropolitan area is new by national standards, having developed primarily since World War II and particularly since 1970. However, settlement patterns were established in the 1800s, in part due to topographic features such as water courses and mountains. The war effort during World War II stimulated the growth of the Valley. After the war, a combination of events led to much faster growth. These included the desire of ex-servicemen stationed in the area during the war to return; improvements in air conditioning; charter government in Phoenix, which allowed a small pro-growth business group to gain power; and
aerospace and electronics firms siting facilities, in part because of the federal government’s designation of Fort Huachuca as the principal proving ground for electronic defense equipment. The modern period began around 1970, when a maturing metro area coincided with the baby-boom generation reaching adulthood. The result was even more rapid growth that has continued to the current time. Rapid growth of the Phoenix metro area is expected to continue for at least the next 50 years. Land and water availability should not restrict growth until after the current population of nearly three million exceeds seven million in 2050.

The Phoenix metropolitan area’s “favored quarter” for employment in 1995 – the metro area’s highest employment densities outside the primary core – extended from Chaparral Road in Scottsdale to Baseline Road in Tempe. Downtown and South Scottsdale’s success can be traced to being adjacent to the favored residential quarter that extends from the area around the Phoenix Mountains through north Scottsdale. In the 1990s, the favored employment quarter has been extending north in Scottsdale through the favored residential quarter. The presence of Arizona State University, proximity to Sky Harbor Airport, and access to the region’s first two freeways contributed to the portion of Tempe north of Baseline Road becoming the largest employment center outside of the primary core in Phoenix. Employment also was above average south of Baseline Road, extending into the secondary favored residential quarter of South Tempe and Ahwatukee – Foothills. Considering residential and economic factors, the Phoenix metro area’s favored quarter stretches from north of Squaw Peak in northeast Phoenix through Paradise Valley, Scottsdale, and Tempe to south of South Mountain in southeast Phoenix.