Cotton, copper and convicts once dominated Pinal County

Zoom in: The Spanish brought in cattle, though sheep ranching was a major, less romanticized industry as well, says Mariel Watt, director of the Pinal County Historical Museum.

• Mining was very important to Pinal County and still is today, but it was very boom-and-bust and "it petered out reasonably fast, like a lot of 19th century mining," Watt tells Axios.
• And Florence benefitted from sixth C — convicts. The Yuma Territorial Prison closed in 1909 and inmates were transferred to a facility in Florence, which became home to Arizona's state prison.

Zoom out: The county's diverse agricultural base gave way to a cotton boom when British supplies of long-staple cotton became scarce during World War I.

• Cotton was used in tire production at the time, and tire companies found ideal growing conditions in Arizona, including in Pinal, Sheridan tells Axios.
• The cotton boom outlived the war, and growers converted to the short-staple variety used for textiles.

The intrigue: Created in 1875, Pinal County was a rock-solid Democratic stronghold for more than a century, but recent new residents brought seismic political changes.

• Paul Babeu in 2008 became the first Republican ever elected Pinal County sheriff, and he was the first to win a countywide office in recent history, per news reports.
• That same year, Bryan Martyn became the first Republican elected to the Pinal County Board of Supervisors, which at the time had only three members.
• Today, registered Republicans outnumber Democrats nearly two-to-one in Pinal.