Organized at indianapolis, indiana and, mustered into service on december 11, 1861. Known as the wildcats the unit would have a strong irish influence in its ranks, evident in an irish regimental flag. The unit would see service in the western theatre, the department of the gulf and texas.Battles: negley’s expedition to chattanooga, perryville, murfreesboro pike, dobbin’s ferry, advance on murfreesboro, stone’s river, tullahoma campaign, chickamauga campaign, chickamauga, siege of chattanooga, chattanooga-ringgold campaign, lookout mountain, mission ridge, ringgold gap, taylor’s ridge, atlanta campaign, tunnel hill, rocky faced ridge, dalton, buzzard’s roost gap, resaca, kingston, cassville, dallas. Operations on line of pumpkin vine creek and battles about dallas, new hope church, allatoona, marietta, kennesaw mountain, pine hill, lost mountain, assault on kennesaw, ruff’s station, smyrna camp ground, chattahoochee river, peach tree creek, siege of atlanta, jonesboro,. Lovejoy station, nashville campaign, columbia, duck river, franklin, nashville, regiment lost during service 5 officers and 82 enlisted men killed and mortally wounded and 164 enlisted men by disease a total loss of 251.The national flag adopts the standard pattern used by the union forces during the civil war and, bears unit designation in gold stencil, but no honours upon it. The regimental colour is unique amongst indiana units which, adopted a dark blue flag with the national arms on the observe and the indiana state seal on the reserve. However; the 35th received a green irish flag adorned with the harp and shamrock with the unit designation in gold on a red scroll. Only one flag associated with the unit is held in the indiana state museum in indianapolis.