Battery K was referenced on a War Department marker at Antietam (now lost) and honored by a monument on the Gettysburg battlefield.

1861
January Stationed at Eagle Pass, Fort Duncan, Texas
February Moved to Fort Taylor, Fla.,
1862
January Moved to Washington, D.C. Attached to Artillery Reserve, Army Potomac
March Moved to Virginia Peninsula
April 5-May 4 Siege of Yorktown
May 5 Battle of Williamsburg
May Attached to 2nd Brigade, Artillery Reserve, 5th Army Corps, Army Potomac
May 31-June 1 Battle of Fair Oaks, Seven Pines
June 25-July 1 Seven days before Richmond
July 1 Malvern Hill
July Assigned to 2nd Brigade, Horse Artillery, Army Potomac
August 16-28 Moved to Fortress Monroe, then to Centerville
August 28-September 2 Pope’s Campaign in Northern Virginia
August 29 Battle of Groveton
August 30
Second Battle of Bull Run
September 1 Chantilly
September 6-22 Maryland Campaign. Attached to Reserve Artillery, 5th Army Corps
September 16-17
Battle of Antietam

The battery was armed with six 12-pounder Napoleons at antietam. It lost four men killed and five badly wounded.

From the marker on the Antietam battlefield:

Captain William M. Graham, commanding

This Battery moved from the bivouac of the Artillery Reserve, near Porterstown, crossed the Antietam at Pry’s Ford, passed the Neikirk farm buildings and, following the ravines, came into position about 40 yards north of this point on the right of Richardson’s Division, and engaged a section of Confederate Battery—two brass guns—about 700 yards southwest, which soon retired. It then assisted in repelling a charge of Confederate Infantry through Piper’s Cornfield. Two Confederate Batteries, rifled guns, now opened on the Battery, one of which enfiladed it and, in an engagement of about thirty-five minutes, it suffered heavy losses. The Battery was unable to reach the enemy, who had rifled guns of greater range than Captain Graham’s smooth-bores, and was withdrawn by General Richardson to avoid useless sacrifice of men and horses. General Richardson was mortally wounded while personally directing the fire of the Battery.

From Captain Graham’s report of the battle:

I feel called upon to mention the conduct of a citizen… who resides near the battle-field. This gentleman drove his carriage to my battery while under a severe artillery fire, and carried off my wounded, who were suffering very much for the want of proper surgical attendance, and distributed ham and biscuit among the men of the battery. He also returned a second time to the battery. One of his horses was wounded while performing this service.

December 11-15
Battle of Fredericksburg
December At Falmouth, Va. Assigned to Artillery Reserve, Army Potomac
1863
April 27-May 6 Chancellorsville Campaign
May 1-5
Battle of Chancellorsville
June 9
Battle of Brandy Station

Commanded by Captain William M. Graham

June 21 Upperville
July 1-3
Battle of Gettysburg

From the monument on the South Cavalry Field at Gettysburg:

Six 3 inch Rifles
Captain William M. Graham, commanding

July 3. Arived on the field and took position on the left with cavalry and engaged during the attack of Brig. General E .J. Farnsworth’s and Brig. General W. Merritt’s Brigades on the Confederate right.

July 6 Williamsburg and Hagerstown, Md.
July 8 Boonsboro
July 9 Benevola or Beaver Creek
July 10-13 About Funkstown
August 1-4 Brandy Station
September 13-15 Advance from the Rappahannock to the Rapidan
September 13 Culpeper Court House
September 15 Robertson’s Ford
October 9-22 Bristoe Campaign
October 12-13 Jeffersontown
November 7-8 Advance to line of the Rappahannock
November 26-December 2 Mine Run Campaign
1864
January 1-4 Reconnaissance from Bealeton to Front Royal
May 4-June 12. Rapidan Campaign
May 5-7
Battle of the Wilderness
May 8-21
Spotsylvania Court House
May 23-26 North Anna
May 28-31 Totopotomoy
June 1-12
Cold Harbor
June 21 Ream’s Station
June 22-30 Wilson’s Raid on Southside & Danville Railroad
June 23 Nottaway Court House
June 28-29 Sappony Church or Stony Creek
June 29 Ream’s Station
July 12-14 Moved to Washington, D.C. Assigned to Camp Barry, D.C.
August 7-
November 28
Sheridan’s Shenandoah Valley Campaign. Attached to Horse Artillery, Army of the Shenandoah, Middle Military Division.
August 25 Near Kearneysville
August 28 Leetown and Smithfield
August 29 Smithfield Crossing, Opequan Creek
September 15 Savior’s Ford, Opequan Creek
September 19
Third Battle of Winchester (Opequan)
September 21
Fisher’s Hill
September 22 Milford
September 23-24 Mt. Jackson
September 26-27 Port Republic
October 19
Battle of Cedar Creek
December Duty in the Defenses of Washington and Shenandoah Valley. Attached to Horse Artillery Reserve, Army of the Shenandoah
1865
April Assigned to Cavalry Brigade, Army of the Shenandoah until August