Organized at Evansville, Indiana, the 25th Indiana Infantry would be mustered into service on August 19, 1861. The next week it would go to St. Louis.
After being sent to Paducah, it would be attached to Jacob Lauman’s Third Brigade, of Charles F. Smith’s Second Division. It would fight in February, 1862, at Forts Henry and Donelson. It would take part in the attack, against the Confederate center, at Fort Donelson that would lead to the Confederate loss.
The 25th Indiana would move to Pittsburg Landing, TN, by March 8, 1862. It was assigned to the Second Brigade of US Brigadier General Stephen Hurlbut’s Fourth Division. Its colonel, James C. Veatchwould be elevated to brigade command with its lieutenant colonel, William H. Morgan commanding the regiment. It would fight at the Battle of Shiloh, April 6-7, 1862, and would suffer severely, near the Crossroads. Total casualties during the fighting would be 139, including Morgan, who would be shot through the leg.
After Shiloh, the 25th would participate in US Major General Henry W. Halleck’s “snail’s paced” siege on Corinth, from April 29 to May 30, 1862. After the Siege of Corinth, the regiment would march to Memphis, where it would remain, until September 6, 1862. The regiment would then be with US Major General Ulysses S. Grant during his central Mississippi campaign, through January 1863.
After the campaign in Mississippi, the 25th Indiana would be sent to Memphis, where it would serve garrison duty through November 1863.
The 25th would fight in several battles, in Alabama, in the spring and summer, of 1864, including Fletcher’s Ferry and Pond Springs. From August 8 – September 8, 1864 the regiment would fight in the battles around Atlanta, including the bloody battle of Jonesboro, August 31 – September 1 and Lovejoy Station, September 2-6.
The regiment would stay with US Major General William T. Sherman, through the March to the Sea, and the Carolinas Campaign. Fighting at Bentonville, NC, March 19-21, 1865, it would serve in US Major General Joseph Mower’s Division of US Major General Oliver O. Howard’s Right Wing – comprising the Army of the Tennessee.
After CS General Joseph Johnston’s surrender, on April 26, 1865, the 25th Indiana would participate in the Grand Review, in Washington D.C., on May 24. The regiment would officially muster out of Federal service, on July 17, 1865. During the course of the war, the 25th would suffer 361 casualties, of all types.