After graduating in 1883, Barber worked as a staff physician at the Pennsylvania Hospital, until he moved to Wyoming.

[2] In 1885, Barber moved to Wyoming to take up a position as surgeon in charge of the military hospital at Fort Fetterman.

He was promoted to Acting Surgeon in the United States Army and accompanied General George Crook's expedition to Arizona, then was assigned to duty at Fort D. A.

[3] After resigning from the United States military, he was in charge of the hospital of the Wyoming Stock Association.

During his administration, he called out state troops to quell a Pine Ridge Indian outbreak and asked for federal assistance with the Johnson County War between cattlemen (WSGA) and cowboys (small time ranchers) in Johnson County in 1892.