[1] Hartshorne moved to California in 1849 and became involved in the ferry business at the Yuma Crossing on the Colorado River with George Alonzo Johnson and other partners from San Francisco.

The two men then contracted to carry supplies up the Colorado in poled barges, but this endeavor failed due to the strong current and many sandbars in the river.

The company brought the disassembled side-wheel steamboat General Jesup to the Colorado River Delta and assembled it with a more powerful 70 hp engine.

There Johnson began successfully shipping cargo and carrying passengers on the Colorado River from its estuary, up to Fort Yuma.

Hartshorne married Julia Norton, a native of Buffalo, New York who moved to San Francisco the previous year in 1862.