In 1863, Moore moved to Blackfoot, Montana and then to Walla Walla, Washington. Arriving penniless, he took a job as a clerk in a general store. In 1869, he partnered with H. E. Johnson and Company to form Paine Brothers and Moore, where he worked until 1877 as a dealer of general merchandise and farm supplies. He married Mary Elizabeth "Molly" Baker on March 26, 1873, and the couple had three sons, Frank Allen, Walter Baker, and Robert L.