Mapping a post-colonial city: How Phoenix grew outside original urban blueprints

Although the state of Arizona was founded 136 years after the country’s establishment in 1776, its urban development didn’t follow Eastern blueprints. 

“Like every city across the United States, Phoenix’s urban development is a function of the technology of the time. That’s also what makes us unique,” said Meagan Ehlenz, an associate professor in the School of Geographical Sciences and Urban Planning at Arizona State University.

The traditional brownstone townhomes and colonial architectural patterns that shaped many Eastern cities never fully took hold in the West. Instead, Phoenix evolved through distinct eras — from Indigenous communities to 19th-century Western settlers — before taking on the form most recognizable today. Its modern landscape emerged during the post-World War II boom, shaped by the rise of automobiles, expanding highways, single-family neighborhoods and the widespread adoption of air conditioning.

“In my mind, Phoenix wasn’t trying to emulate any specific city, but was more a product of ambition and the confluence of development technologies that made growth possible. We are such a pro-development city, and that’s really been our story for such a long time,” said Ehlenz.

When studying capital cities across the U.S., including Washington, D.C., New York and Boston, their influences largely come from Europe and draw from grand architectural traditions while implementing organized grid structures. Despite Phoenix’s capital city planning drawing some inspiration from its Midwestern and Eastern peers, the city reflects newer urban planning and development technologies. 

“After decades of no new development nationally, due to the Great Depression and the demand for resources to flow towards WWII efforts, the 1950s and 1960s unleashed the desire to build and grow,” said Ehlenz. “This was fueled not only by trends in the private sector, but also by sweeping federal programs that supported highway expansion and homeownership. Those national trends were the foundation of what played out in Phoenix.”

Because Phoenix missed the original waves of development during eras such as the Industrial Revolution, the land provided a blank canvas for later development using post-1950s technology. In comparison, cities in the Midwest and the East Coast had existing infrastructure, such as dense housing to support residents employed at nearby warehouses and industrial districts. 

The lack of existing infrastructure meant that Phoenix had a development sector ready to quickly build, allowing the city to form in a modern way, fueled by large-scale master-planned areas.

Jason Kelley, a teaching professor in the school, has a background in U.S. urban planning history and has studied East Coast and South American cities during different time periods. One contributor to how Phoenix was designed is discussed in one of his classes: transportation planning and history. He presents four different eras of transportation innovations that had a significant impact on the way a city appeared and was built. One era Phoenix did not experience throughout the 1800s was horse carsTypically refers to the historical 19th-century public transit rail cars pulled by horses.. 

“Cities were dense, compact and built for walking, and of course, the East Coast cities were already large cities by this point, so they had infrastructure built for pedestrians. Housing that was dense, including row houses and the brownstones that you see back in places like Baltimore and Boston that we don't have here,” said Kelley. “The original town site for Phoenix wasn't even laid out until 1870, and the town wasn't incorporated until 1881. We were in our infancy by the time the next innovation hit, which was the electric streetcar.”

Phoenix took advantage of the original streetcars before the 1920s, when the automobile industry took off. By 1946, the city pulled its last streetcar and became automobile-dependent from then on. 

“When you look at the map of Phoenix, it was such a small area, and all the way up until 1950, Phoenix was a small city. Then came air conditioning, the flood of people with their automobiles, and Phoenix grew rapidly, doubling in size in that one decade alone. We aggressively annexed land,” said Kelley. 

Kelley emphasized that the missing high-density residential buildings that are normally seen in the eastern United States were replaced by single-family homes and apartment complexes that instead emphasized the need for an automobile throughout the Sun Belt citiesA region comprising 15 southern states in the United States and extending from Virginia and Florida in the Southeast through Nevada in the Southwest, and also including southern California.. 

In efforts to combat automobile reliance, Phoenix planners and voters in the late 1970s enacted an idea surrounding the urban village concept, where subcore areas would pop up surrounding the downtown area and promote densification within the cores to make them more walkable.

“It's kind of an extra layer that we've added on that I don't think all cities necessarily have, perhaps a little bit unique and helps to shape the city and, hopefully, I think, make it a little bit better,” said Kelley. “It’s trying to create some distinctive nodes within and in the future will be able to connect those nodes better with public transit.”

Looking toward the future of urban development throughout the Phoenix-metro valley, Kelley hopes the development of middle-type housing — a multi-unit building option in between single-family houses and apartment complexes — enables better opportunities to expand the current light rail system. 

“Until we start to have higher-density residential areas, we're not going to be able to expand our rail and transit system very effectively in an automobile-dependent city. I really think for the future of the city, for its sustainability, it's got to look within the city limits and not continue outward growth and gobbling up our desert on the fringe of the city,” said Kelley. 

Similarly, Ehlenz looks at the opportunities to go through the city’s first major round of redevelopment and reimagine how the city’s neighborhoods could look to welcome more density. 

“We have exciting urban nodes already, and we’ve made some interesting investments in public transportation to reimagine our car-oriented history,” said Ehlenz. “What will it look like as we embrace those ideas more fully and allow them to really take hold in our desert city? That’s what I think is among the most exciting and important urban planning questions for Phoenix.”