Phoenix Union Station, circa 1975 (Photographer unknown).
When Jefferson Davis — yes, that Jeff Davis — led the pre-Civil War survey for a southern route of the transcontinental railroad, Phoenix didn't exist. The Salt River Valley still lay in its centuries of enchanted slumber surrounded by wilderness. So the line was set in an arc north and west out of Tucson toward California. This necessitated the Gadsden Purchase from Mexico — otherwise, today's international border would be at the Gila River. But it also meant that what became the nation's fifth most populous city would end up without a mainline railroad. Even when the Southern Pacific was built across Arizona in the 1880s, Phoenix was a mere hamlet. It was served by a spur from Maricopa.
By 1910, Phoenix was the territorial capital. With more than 11,000 people, it was fast overtaking Tucson as the territory's largest town — and with the Salt River harnessed by Roosevelt Dam it would become the center of huge agricultural production. In 1923, the SP and Santa Fe railways remedied this, by building this Spanish Colonial revival station. Three years later, the SP built a northern main line up from Picacho Junction through Phoenix and west to where it joined the southern main just east of Yuma. It was a matter of competitive urgency, because the rival Santa Fe railroad had built a line to Phoenix (the Peavine) from its northern Arizona main at Ash Fork, and another that broke off west from Wickenburg to California. The SP's line was opened in 1926 and waiting for Phoenix's transcontinental railroad was the grandest building in this city of 48,000: the lovely mission-revival style Union Station.
It's still there, at 4th Avenue and Harrison Street, the best human-made reminder I know of that Phoenix indeed has history and soul. Because of terrible short-sightedness of state leaders, it hasn't been served by Amtrak trains since 1996. It held telecommunications equipment for Sprint, which began as an SP subsidiary, until 2020 and now it's being used as an events space. Being a telecom barn was a horrid missed opportunity to create something great downtown — as Denver did. I was fortunate enough to see Union Station at the end of its glory days.