The California Column
Light Battery A, Third United States Artillery
First Lieutenant John B. Shinn, Commanding
Lieutenant Shinn's
Battery was comprised of two six pound guns and two twelve pound
howitzers.
There were also two ad-hoc batteries manned by "selected infantrymen and unassigned recruits". Each battery,
one commanded by First Lieutenant William Thompson (Co. E, 1st Calif. Infantry) and one by Second Lieutenant
Jeremiah Phelan (Co. K, 1st Calif. Infantry) had two mountain howitzers.
Both were referred to as "Jackass Batteries", at various times, by other members of the California Column.