The regiment lost during service 8 officers and 117 enlisted men killed or mortally wounded and 2 officers and 123 enlisted men to disease during the Civil War.

1861
October 4 Company B organized in Michigan
Company C in Pennsylvania
October 5 Company A organized in Minnesota
November 2 Company D organized in Maine
November 9 Company E organized in Vermont
November 28 Company F organized in New Hampshire
December 10 Company G organized in New Hampshire
December 31 Company H organized in Vermont
October-December Companies moved to Washington, D.C. and duty in the Defenses of that city
1862
January 1 Lieutenant Colonel Henry Post was promoted to colonel.
March Attached to Augur’s Brigade, King’s 1st Division, McDowell’s 1st Army Corps, Army of the Potomac
April 5-6 Moved to Bristoe Station, Va. and attached to 1st Brigade, King’s Division, Dept. of the Rappahannock
April 15-19 To Falmouth, Va.
May 25-29 McDowell’s advance on Richmond
June 1-21 Operations against Jackson. Attached to 1st Brigade, 1st Division, 3rd Army Corps, Army of Virginia
July-August Duty at Falmouth
July 19 Blackburn’s Ford
July 24-26 Reconnaissance to Orange Court House
August 16-September 2 Pope’s Campaign in Northern Virginia
August 21-23 Fords of the Rappahannock
August 26 Sulphur Springs
August 29
Battle of Groveton
August 30
Second Battle of Bull Run
September 6-22 Maryland Campaign. Attached to 1st Brigade, 1st Division, 1st Army Corps, Army of the Potomac
September 14
Battle of South Mountain
September 16-17
Battle of Antietam

Colonel Post was wounded.

From the brigade marker on the Antietam battlefield:

Phelps’ Brigade formed line at 5:30 A. M. on September 17, and moved in support of Gibbon’s Brigade. When Gibbon deployed, 135 yards north of this in the Cornfield and on the plateau west of the Hagerstown Pike, Phelps’ Brigade (425 officers and men) halted 25 paces in his rear, in the Cornfield. After Gibbon advanced and became heavily engaged on both sides of the Pike, Phelps moved to the support of his left and fought on this ground. The subsequent movements of this Brigade conformed to those of Gibbon. After heavy loss it retired to the fields north of D. R. Miller’s and thence beyond the Poffenberger Lane.

September-October Camp near Sharpsburg
October 29-November 17 Movement to Falmouth, Va.
November 16 Colonel Post resigned. Colonel Hiram Berdan was assigned to command of the regiment.
December 12-15
Battle of Fredericksburg
1863
January 20-24 “Mud March”
February-April At Falmouth
March Attached to 3rd Brigade, 3rd Division, 3rd Army Corps, Army of the Potomac
April 27-May 6 Chancellorsville Campaign
May 1-5
Battle of Chancellorsville
June 11-July 24 Gettysburg Campaign
June Attached to 2nd Brigade, 1st Division. 3rd Army Corps
July 1-3
Battle of Gettysburg
July 5-24 Pursuit of Lee
July 23 Action at Wapping Heights, Va.
September Attached to 3rd Brigade, 1st Division, 3rd Army Corps
October 9-22
Bristoe Campaign
October 14 Auburn and Bristoe
November 7-8 Advance to line of the Rappahannock
November 7 Kelly’s Ford
November 8 Brandy Station
November 26-December 2
Mine Run Campaign
November 27 Payne’s Farm
1864
February 6-7 Demonstration on the Rapidan
March Attached to 1st Brigade, 3rd Division, 2nd Army Corps
May 4-June 15 Campaign from the Rapidan to the James River
May 5-7
Battle of the Wilderness
May 8-21 Laurel Hill
May 8-12
Spotsylvania Court House
May 10 Po River
May 12 Assault on the Salient, “Bloody Angle”
May 19
Harris Farm, Fredericksburg Road
May 23-26
North Anna River
May 26-28 On line of the Pamunkey
May 28-31 Totopotomoy
June 1-12
Cold Harbor
June 16-19 Before Petersburg
June 16 –
February 20
Siege of Petersburg
June 22-23 Jerusalem Plank Road, Weldon Railroad
July 27-29 Demonstration north of the James River
July 28-29 Deep Bottom
August 13-20 Demonstration north of the James
August 14-18 Strawberry Plains, Deep Bottom
September 29-October 2 Poplar Springs Church, Peeble’s Farm
October 27-28 Boydton Plank Road, Hatcher’s Run
December 7-12 Expedition to Weldon Railroad
1865
February 5-7 Dabney’s Mills, Hatcher’s Run
February 20 The regiment was discontinued and its companies assigned to volunteer regiments:

Company A transferred to 1st Minnesota Infantry
Company B to 5th Michigan Infantry
Company C to 105th Pennsylvania Infantry
Company D to 17th Maine Infantry
Companies F & G to 5th New Hampshire Infantry
Company H to 4th Vermont Infantry