The 1st Maine Cavalry was mustered for three years' service on October 31, 1861 and mustered out on August 1, 1865. Of the 3226 men enrolled in the regiment, 154 were killed or died of wounds, 171 died of disease, and 165 died in Confederate prisons. This regiment lost the greatest number killed in action of any cavalry regiment in the entire army.

They served in the following engagements:

• First Bull Run - July 21, 1861
• Middleton, VA. - May 24, 1862
• Winchester, VA - May 25, 1862
• Luray, VA - June 1862
• Cedar Mountain VA - August 9, 1862
• Brandy Station, VA - August 20, 1862
• Rappahannock Station, VA - August 24, 1862
• Thoroughfare Gap, VA - August 28, 1862
• 2nd Bull Run, VA - August 28-29, 1862
• Frederick, MD - September 12, 1862
• South Mountain, MD - September 13-14, 1862
• Antietam, MD - September 17, 1862
• Fredericksburg, VA - December 12-13, 1862
• Dumfries, VA - December 28, 1862
• Rappahannock Station, VA - April 14, 1863
• Louisa Court House, VA - May 2, 1863
• Stoneman's Raid, VA - May 5-7, 1863
• Bealton, VA - May 10, 1863
• Brandy Station, VA - June 9, 1863
• Aldie, VA - June 17, 1863
• Middleburg, VA - June 17, 1863
• Upperville, VA - June 21, 1863
• Aldie, VA - June 22, 1863
• Gettysburg, PA - July 1 - 3, 1863
• Halltown, WV - July 15, 1863
• Shepardstown, WV - July 16, 1863
• Sulphur Springs, VA - October 12, 1863
• Mine Run, VA - November 30, 1863
• Fortification of Richmond
• Dahlgren Raid, VA - February 29 - March 2, 1864
• Strasburg, VA - May 1, 1864
• Todd's Tavern, VA - May 8, 1864
• Beaver Dam Station, VA - May 10, 1864
• Ground Squirrel Bridge, VA - May 11, 1864
• Sheridan's Raid, VA
• Hawe's Shop, VA - May 28, 1864
• Cold Harbor, VA - June 2, 1864
• Trevillian Station, VA - June 11, 1864
• St. Mary's Church, VA - June 24, 1864
• Malvern Hill, VA - July 28-29, 1864
• Berryville, VA - August 14, 1864
• White Tavern, VA - August 15, 1864
• Deep Bottom , VA - August 16, 1864
• Charles City Crossroads, VA - August 18, 1864
• Reams Station, VA - August 23-25, 1864
• Stony Creek, VA - September 16, 1864
• Wyatt Farm, VA - September 29, 1864
• Vaughan Road, VA - October 1, 1864
• Boydton Plank Road, VA - October 27, 1864
• Bellefield, VA - December 10, 1864
• Hatcher's Run, VA - February 5, 1865
• Dinwiddie Court House, VA - March 31, 1865
• Fame's Crossroads, VA - April 5, 1865
• Lee's Train, VA - April 6, 1865
• Sailor's Creek, VA - April 6, 1865
• Farmville, VA - April 7, 1865
• Appomattox, VA - April 9, 1865