In November 1852, Uncle Sam, a 65-foot (20 m) long side-wheel paddle steamer was brought by the schooner Capacity from San Francisco to the Colorado River Delta by the next contractor to supply Fort Yuma, Captain James Turnbull.
Equipped with only a 20-horsepower (15 kW) engine, Uncle Sam could only carry 35 tons of supplies, taking 15 days to make the first 120-mile (190 km) trip.
Negligence caused it to sink at its dock below Fort Yuma, and was then washed away and lost before it could be raised, in the spring flood of 1853.
Turnbull who meanwhile had returned to the Delta from San Francisco with another cargo and a more powerful engine for the Uncle Sam.
Nevertheless, Turnbull had shown the worth of steamboats to solve Fort Yuma's supply problem.