The 4th United States Artillery, Battery E is is referenced on a War Department marker at Antietam and honored by a monument at Gettysburg.

1861
April Organized at Camp Monroe, Ohio, and Joined Rosecrans in West Virginia. Duty in West Virginia attached to 2nd Brigade, Army of Occupation, West Virginia.
September Attached to Scammon’s Brigade, Dept. of West Virginia
October Attached to Kelly’s Command, Railroad District, West Virginia
1862
January Attached to Artillery, Lander’s Division, Army of the Potomac
March Attached to Artillery, Shields’ 2nd Division, Banks’ 5th Army Corps
March 7-12 Advance on Winchester, Va.
March 23 Battle of Winchester
April 4 Attached to Artillery, 2nd Division, Department of the Shenandoah
April 17 Occupation of Mt. Jackson.
May 10-21 March to Fredericksburg. Attached to Dept. of the Rappahannock
May 25-30 Return to Front Royal
June 8-9 Battle of Port Republic
June Attached to 3rd Corps, Army of Virginia
August 16-September 2 Pope’s Campaign in Northern Virginia
August 20-23 Fords of the Rappahannock
August 27 Bristoe Station
September Attached to Artillery, 2nd Division, 9th Army Corps, Army of the Potomac
September 6-22 Maryland Campaign
September 16-17
Battle of Antietam

The battery brought 59 men to the field and was armed with four 10-pounder Parrott rifles. it was commanded at Antietam by Captain Joseph C. Clark, Jr. until he was badly wounded by the same case shot that killed Lieutenant Baker and an enlisted man. Sergeant Christopher F. Merkel took command of the battery for the rest of the battle.

From the War Department marker on the Antietam battlefield:

At daybreak Battery E, 4th U.S. Artillery, was in bivouac in rear of the high ground east of the Burnside Bridge. Soon after daybreak it took position on the ridge overlooking the Antietam and the field of battle north and west, and about 685 yards a little east of north from the bridge, and opened fire upon the Confederate Infantry north of Sharpsburg. When this fire ceased to be effective, the Battery moved to the western slope of the bluff immediately opposite the bridge and but 240 yards from it, and shelled the Confederate Infantry defending it. It followed the infantry of Sturgis’ Division across the bridge and went into battery on the crown of the ridge due west of the bridge and about 580 yards northeast of this point. While going into position spherical case shot from a Confederate battery killed Lt. W. L. Baker, severely wounded Capt. Clark, and the command devolved on Sergeant C. F. Merkel, who fought the battery until the close of the action.

October 16-17 Reconnaissance to Charlestown
October 16 Charlestown
October 22 Sergeant Merkel was promoted to lieutenant.
October 30-November 19 Movement to Falmouth, Va.
December 12-15
Battle of Fredericksburg

Commanded by Lieutenant George Dickinson, who was killed.

1863
January 20-24 “Mud March”
February Attached to Reserve Brigade, 1st Cavalry Division, Cavalry Corps, Army of the Potomac
April 14-15 Operations at Welford’s, Kelly’s and Beverly Fords
April 27-May 6 Chancellorsville Campaign
May Attached to 1st Brigade, Horse Artillery, Army of the Potomac
June 9
Battle of Brandy Station 

Commanded by Lieutenant Samuel S. Elder

June 30 Hanover, Pa.
July 1-3
Battle of Gettysburg

The battery was commanded at Gettysburg by Lieutenant Samuel S. Elder. It was armed with four 3″ rifles, and lost one man killed.

From the monument on Bushman Hill at Gettysburg:

July 3 Arrived on the field and took position on a hill southwest of Round Top and engaged under Brig. General E. J. Farnsworth in the afternoon against the Confederate right.

Casualties: killed 1 man

July 4 Hunterstown, Pa.
July 8 Boonsboro, Md.
July 10-13 Hagerstown
July 14 Falling Waters
September 1-3 Expedition to Port Conway
September 13-17 Advance from the Rappahannock to the Rapidan
September 13 Culpeper Court House
October 9-22 Bristoe Campaign
October 10 James City, Bethesda Church and near Culpeper
October 11 Brandy Station
October 14 Gainesville
October 17-18 Groveton
October 19 Gainesville, New Baltimore, Buckland’s Mills and Haymarket
November 7-8 Advance to line of the Rappahannock
November 26-December 2 Mine Run Campaign
1864
May 4-June 12 Rapidan Campaign
May 5 Craig’s Meeting House
May 5-6 Todd’s Tavern
May 6-7
Battle of the Wilderness
May 9-24 Sheridan’s Raid to the James River
May 9 North Anna River
May 11
Ground Squirrel Church and Yellow Tavern
May 12 Brook Church and fortifications of Richmond, Strawberry Hill
May 26-28 On line of the Pamunkey
May 28-31 Totopotomoy
June 1-12
Cold Harbor
June 2 Totopotomoy
June 12 Long Bridge
June 13 Riddell’s Shop and White Oak Swamp
June 16-August 5 Siege of Petersburg
June 22 Ream’s Station
June 22-July 1 Wilson’s Raid on Southside & Danville Railroad
June 23 Nottaway Court House
June 25 Staunton River Bridge
June 28-29 Sappony Church, Stony Creek
June 29 Ream’s Station
August 7-
November 28
Sheridan’s Shenandoah Valley Campaign. Attached to Artillery, 1st Division, Cavalry Corps (Horse Artillery Reserve), Army of the Shenandoah, Middle Military Division
November 28-December 3 Expedition from Winchester into Faquier and Loudoun Counties
December 19-28 Expedition to Gordonsville
December 22 Liberty Mills
1865
February 27-
March 25
Sheridan’s Raid from Winchester
March 2 Occupation of Staunton and action at Waynesboro
March 8 Duguidsville
March Horse Artillery Reserve, attached to 3rd Division, Cavalry Corps, Army of the Potomac
March 28-April 9 Appomattox Campaign
March 30-31 Dinwiddie Court House
April 1
Five Forks
April 2 Scott’s Cross Roads
April 4 Tabernacle Church or Beaver Pond Creek
April 6 Sailor’s Creek
April 8 Appomattox Station
April 9
Appomattox Court House

Surrender of Lee and his army.

April 23-29 Expedition to Danville
May Moved to Washington, D.C.
May 23 Grand Review
May Duty at Washington, D.C., until August attached to Horse Artillery Brigade, 22nd Army Corps