[1] Nash was born in Chautauqua County, New York in about 1836, and at the age of 22 in 1858, he moved to Missouri.

During the American Civil War, Nash was commissioned a Major in the 12th Missouri Volunteer Cavalry Regiment in 1864, and he participated in the Franklin–Nashville Campaign and fought with the regiment in Tennessee and Alabama, most notably at the Battle of Nashville in December of that year.

In the summer and fall of 1865, the 12th Missouri Cavalry Regiment, including Major Nash, accompanied the Powder River Expedition through the present-day states of Nebraska, South Dakota, Montana, and Wyoming, fighting against Sioux and Cheyenne Indians in the Powder River Battles.

After the war, he returned to Missouri, but moved to Washington in 1883, and engaged in milling and merchandising.

Nash staked a homestead near Molson, Washington, and carried the mail between Chewsaw and Oroville.