At a glance: The 1910s gave Scottsdale the three things every western town prayed for — water, statehood, and a cash crop. Roosevelt Dam was dedicated in 1911, Arizona joined the union in 1912, and World War I turned Pima cotton into white gold. The boom tripled the town, brought the Mexican-American families who would build much of its future, and set up the crash that opens the next chapter.
1911: the water arrives for good
On March 18, 1911, Theodore Roosevelt stood on the dam that bore his name and declared it one of the achievements he was proudest to be associated with. For Scottsdale, 80 miles downstream, the speech was almost beside the point — what mattered was the reservoir filling behind the masonry. After two decades of praying over river flows, Valley farmers had guaranteed, year-round irrigation water.
The effect showed immediately in the fields and on the tax rolls. Alfalfa, grain, dates, and orchards spread; farmhouses got second stories; and in 1913 merchant-farmer Charles Miller built the kind of substantial home that announced the frontier was over.
Eleven months after the dedication, on February 14, 1912, Arizona entered the Union as the 48th state. Scottsdale marked statehood as an unincorporated village of perhaps 300 people — it would stay unincorporated, governed by county and school board, for another 39 years.
The war that planted cotton to the horizon
When the United States entered World War I in 1917, the military discovered it had a fiber problem. Truck and airplane tires, balloon fabric, and aircraft wings all demanded extra-long-staple cotton, most of it previously imported from Egypt — and U-boats had opinions about that supply line. The substitute was growing 30 miles from Scottsdale: the USDA’s experimental farm at Sacaton, on the Gila River Indian Community, had perfected an American long-staple variety named Pima cotton in honor of the Akimel O’odham farmers who developed it.
Prices went vertical, and the Salt River Valley went cotton-mad. Scottsdale farmers ripped out alfalfa and orchards and planted fencerow to fencerow; by 1920 the Valley had on the order of 180,000 acres in cotton. Gins ran around the clock, and for two or three delirious years this quiet Baptist farm town was a boomtown in everything but saloons.
The families the boom brought
Cotton is hungry for labor, and the boom drew Mexican and Mexican-American families to Scottsdale — many recruited directly from Sonora and Chihuahua by Valley growers. They picked, ginned, ditched, and hauled; they were also systematically paid less and housed worse than Anglo workers, settling in a barrio of adobe homes south and east of the townsite.
What the growers treated as temporary labor became permanent community. Families like the Corrals and Coronados stayed through the crash, opened businesses, and within a generation had built some of Scottsdale’s most enduring institutions — including the Old Adobe Mission, raised by hand in 1933. Meanwhile Pima farmers from the Salt River community east of town were part of daily commerce; the row where their wagons tied up on First Avenue was known as Pima Plaza.
The armistice bill comes due
The guns stopped in November 1918, and wartime procurement stopped with them — though cotton prices, running on momentum and speculation, kept climbing into 1920. Every farmer in the Valley knew the smart move was to diversify back out of cotton, and almost nobody did. Scottsdale ended the decade richer than it had ever been, at roughly triple its 1910 population, with its entire economy staked on a single commodity whose price was about to fall off a cliff.
The 1920s open with that crash — and with Scottsdale’s improbable discovery that the same desert that grew cotton could grow something far more profitable: tourists.