In recognition of his service, in 1866 he was nominated and in 1867 he was confirmed for appointment to the grade of brevet brigadier general in the regular army to rank from March 13, 1865.

Following the Mexican War, Eaton was stationed on the frontier where he painted a series of landscapes in New Mexico in the 1850s.

Those paintings are highly sought after by art collectors and museums today and even Eaton's autograph is sold at auction.

[2] At the start of the American Civil War, Eaton was aide-de-camp and military secretary to Maj. Gen. John C. Frémont and was paymaster of the Department of Kansas.

[4] After the Civil War Eaton was assigned to Fort Vancouver where he was the Army's Chief Paymaster of the Department of the Columbia until his retirement in 1881.