Overview
The 45th Indiana Regiment, also known as the 3rd Indiana Cavalry, served in the Union Army during the American Civil War. Organized in 1861, this cavalry regiment was unique in its structure, with companies serving in both the Eastern and Western Theaters. The regiment was mustered in at Madison, Indiana, and operated under the command of several officers throughout its service. It is notable for its split deployment, with the right wing serving with the Army of the Potomac and the left wing operating in Kentucky and later with Western armies.
The 3rd Indiana Cavalry participated in numerous major campaigns and battles, including Antietam, Gettysburg, Stone’s River, and the Atlanta Campaign. The regiment was mustered out on August 7, 1865, at Indianapolis, Indiana.
Organization & Service
The 45th Indiana Regiment (3rd Indiana Cavalry) was organized in 1861. Six companies (A–F), originally intended for the 1st Indiana Cavalry, were organized at Madison on August 22, 1861, and sent to the Army of the Potomac under Lieutenant Colonel Scott Carter. These were joined on October 22, 1861, by four companies (G–K) that had been accepted in September and October and sent to Kentucky, forming a ten-company regiment designated as the 3rd Indiana Cavalry. In December 1862, two additional companies (L and M) were organized and added to the regiment.
The right wing (A–F) joined Hooker’s division at Budd’s Ferry, Maryland, in December 1861. Several companies were detached for anti-contraband operations in Maryland. The regiment remained on duty in lower Maryland until May 1862, then moved to Washington and participated in operations at Thoroughfare Gap, Luray, Front Royal, and Bristoe Station. It was attached to General King’s command at Falmouth and engaged in scouting and skirmishing south of Fredericksburg. The right wing took part in the Maryland Campaign, including South Mountain and Antietam, and later fought at Philomont, Union, Upperville, and Barber’s Crossroads. The regiment was in reserve at Fredericksburg and participated in cavalry actions at Rapidan Ford, Beverly Ford, Upperville, and Gettysburg, where it played a key role on June 30 and July 1, 1863. After Gettysburg, it joined in the pursuit of Lee’s army and saw action at several locations, including Williamsport and Brandy Station. In 1864, it joined Kilpatrick’s raid and Sheridan’s cavalry operations, fighting at Craig’s Meeting House, Spotsylvania, Yellow Tavern, Meadow Bridge, Hanover Court House, Salem Church, Long Bridge, White Oak Swamp, and other engagements. In August 1864, non-veterans were mustered out, and the remaining veterans and recruits formed a battalion that served in the Shenandoah Valley, participating at Opequon Creek, Cedar Creek, Five Forks, Sailor’s Creek, and Appomattox Court House. The regiment was mustered out at Indianapolis on August 7, 1865.
The left wing (G–K) served in Kentucky, attached to various commands, and joined the movement toward Nashville after Shiloh. It participated in the Corinth campaign, operations in Alabama and Tennessee, and the Battle of Stone’s River. The battalion continued with Rosecrans’ army through the Tullahoma and Chickamauga campaigns, and at Missionary Ridge. In late 1863, it moved into eastern Tennessee, engaged in scouting, and was joined by Companies L and M. The battalion joined the Atlanta Campaign and marched with Sherman’s cavalry through Georgia. At Savannah, remaining veterans and recruits were consolidated with the 8th Indiana Cavalry and served until mustering out at Lexington, North Carolina, July 20, 1865.
Research This Regiment Further
If you’d like to explore this unit’s history in more depth, regimental histories and Civil War reference works offer valuable detail.
Engagements & Campaigns
- Duty in lower Maryland (1861–1862)
- Thoroughfare Gap, Luray, Front Royal, Bristoe Station (May–July 1862)
- Maryland Campaign: South Mountain, Antietam (September 1862)
- Philomont, Union, Upperville, Barber’s Crossroads (late 1862)
- Fredericksburg (reserve), Rapidan Ford (April 1863)
- Beverly Ford, Upperville (June 1863)
- Gettysburg (June 30–July 1, 1863)
- Pursuit of Lee: Williamsport, Boonsboro, Beaver Creek, Funkstown, Falling Waters, Chester Gap, Brandy Station, Rappahannock
- Kilpatrick’s Raid, Sheridan’s Raid, Craig’s Meeting House, Spotsylvania, Yellow Tavern, Meadow Bridge, Haxall’s Landing, White House, Chesterfield, Hanover Court House, Salem Church, Long Bridge, White Oak Swamp, Riddle’s Shop, Nottoway Court House, Roanoke Station, Stony Creek (1864)
- Opequon Creek, Cedar Creek, Five Forks, Sailor’s Creek, Appomattox Court House (1864–1865)
- Shiloh, Corinth, Stone’s River, Tullahoma Campaign, Chickamauga, Missionary Ridge, Atlanta Campaign, March to the Sea (for left wing companies)
Casualties
- Total losses: 605
- Killed or died of wounds: 81
- Wounded: 232
- Taken prisoner: 107
- Deserted: 7
- Discharged for disability: 17
- Loss by death (aggregate): 133
- Desertion (aggregate): 65
- Unaccounted for: 319
Some figures are drawn from regimental and state reports; numbers may vary slightly between sources.
Field Officers & Commanders
- Colonel Scott Carter
- Colonel George H. Chapman
- Lieutenant Colonel Jacob S. Buchanan
- Lieutenant Colonel George H. Chapman
- Lieutenant Colonel Robert Klein
- Major George H. Chapman
- Major Charles Case
- Major William S. McClure
- Major Robert Klein
- Major Charles Lemon
- Major William Patton
- Major Benjamin Q. A. Gresham
- Major George H. Thompson
- Major Alfred Gaddis
Regimental Roster
The complete roster of officers and enlisted men who served in the 45th Indiana Regiment (3rd Indiana Cavalry) is available on the regiment’s roster page. This resource provides names, ranks, and service details valuable for genealogical and historical research.
To view the full roster, visit the 45th Indiana Regiment (3rd Indiana Cavalry) Roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I, various volumes and parts (see Army of the Potomac and Army of the Cumberland reports, 1861–1865)
- Indiana Adjutant General’s Report
- Dyer, Frederick H. “A Compendium of the War of the Rebellion”
- Fox, William F. “Regimental Losses in the American Civil War”
- “The Union Army,” Federal Publishing Company, 1908, Volume 3