HEADQUARTERS U. S. FORCES,
Fort Magruder, Va., September 4, 1864.

Major WICKHAM HOFFMAN,

Assistant Adjutant-General, District of Eastern Virginia:]

SIR: I am sorry to report the loss of three of my command belonging to Troop H, Twentieth New York Cavalry, in the following manner: I received a telegram to send an ambulance for three sick men to Jamestown Island. I accordingly ordered an ambulance and sent to Lieutenant Lee, commanding Troop H, for an escort, but he could furnish only three men, one of whom was a corporal just come off picket duty. They started with the ambulance, and when within about a mile of Jamestown Island they were fired upon from the woods by a party of fifteen guerrillas. The corporal was killed and the privates either killed, wounded, or taken prisoners, but the ambulance driver escaped with his vehicle while the cavalry were fighting. The body of the corporal has been recovered, but no traces of the privates. The horses of the corporal and one private came in after the ambulance. There were marks of blood upon them. The other horse was captured. Upon learning of the occurrence by telegram I sent a squad of twenty-one men (all that could be got together-some of them sick), under Lieutenant Lee, whose report I herewith forward. I would urgently request an additional force of cavalry at this post. The two companies I have lost were invaluable, they being intimately acquainted with the country, having been here for more than a year. I have captured through these companies 1 commissioned officer, 3 privates of the Fifth Virginia Cavalry, and a few guerrillas. I am called upon for guards at all the Government farms between Fort Monroe and Fort Magruder. I have not half the command to perform the guard duty required. A large number of my own regiment are sick, and a majority of the cavalry are in the same condition. My men are on duty every other day for picket.

I remain, sir, very respectfully, your obedient servant,

J. J. MORRISON,

Colonel, Commanding Post.

[Inclosure.]

HDQRS. TROOP H, TWENTIETH NEW YORK CAVALRY,
Fort Magruder, Va., September 4, 1864.

Colonel J. J. MORRISON,

Commanding Fort Magruder:

COLONEL: In accordance with orders received from you September 3, 1864, I proceeded to Jamestown Island in search of the guerrilla party who fired upon ambulance guard from Company H, Twentieth New York Cavalry. I scoured the country within ten miles of the place of attack, but could discover none of the enemy. I succeeded in recovering the body of the corporal in charge of guard, who was found with fourteen buckshot holes in his body; I also recovered 2 horses and equipments, 1 Sharps carbine, and one saber. The guard were fired on from ambush, and lost 1 man killed and 2 taken prisoners (one of them badly wounded), 1 horse and equipments, 2 Sharps carbines, and 2 sabers. On inquiry I found a number of the citizens in the neighborhood away from home, and in some cases their families were unable to tell where they were. I have no doubt that the guerrilla party in question was composed of citizens of that neighborhood. In order to get together a sufficient number of men to make this trip I was forced to take the men who had just been relieved from twenty-four hours' picket