[1] By August 1868, Keenan was serving as a private in Company B of the 8th Cavalry Regiment.

[2] Over the next two months, his company was constantly engaged in fights against the Hualapai in northwestern Arizona Territory.

[1] For his actions during these engagements, Keenan was awarded the Medal of Honor the next year, on July 24, 1869.

Afterward, he was sent to Fort Stanton, New Mexico, to recover from a wound received in battle.

During one of these chores, a burning ember hit him in the eyes, leaving him nearly blind.