What was a "striker" in the 1870s US Cavalry?

by EnriqueRoz

I am reading a book about Custer's defeat at the Little BigHorn and the author keeps identifying certain individual troopers as a senior officer's striker. "He was Custer's striker." "So and so was Benteen's striker."

The book is A Terrible Glory.

PachydermicTidalWave

A "Striker" is an old Army term for an enlisted man that would take on assistant duties for an officer in exchange for extra pay.