[3] During the colonial militia buildup at the onset of the American Revolution, on 12 Sep 1775, Buckner was elected lieutenant colonel of the minutemen raised by the combined Virginia counties of Spottsylvania, Caroline, Stafford, and King George under Col. Hugh Mercer.

Having served under George Washington during the earlier war, he was not long after appointed commander of the 6th Virginia Regiment in the nascent Continental Army.

Initially assigned to the Southern Department, the unit transferred to Stephen's Brigade in Washington's main army on 3 September 1776.

Sir: It is not in my power to comply with your request on three Accounts, yourself, the Country at large, and the State you come from, Were the matter to remain undetermined, your Reputation must be ruined; at all events, every Officer would have reason to expect equal favor, and I shall be justly taxed with partiality.

Resolved as I am to reward merit, and punish demerit, I shall refer your case to the judgment of a Court Martial, and shall be happy to hear that it acquits you.

Inst: whereof Brigadier General St. Clair was President, for the trial of Col Mordecai Buckner, accused of "Shamefully Misbehaving before the Enemy, in the Action of the 23rd.

of Jan'y last," And of "Quitting his post and party in time of engagement," have after mature consideration, sentenced the said Col Mordecai Buckner, to be cashiered, and declared incapable of any military office, in the service of the United States.

The General and Commander in Chief approves the sentence, and orders the said Col Mordecai Buckner, forthwith to depart the American Army.[12]Capt.