Joseph enlisted in Co. C, 38TH IND INF on Sept. 18, 1861. He successfully avoided personal injury in several major battles, including Perryville, Stones River, Chickamauga, Lookout Mountain, and Missionary Ridge, during the first 2½ years of his time with the regiment. Baker, along with 216 others, decided to reenlist as a veteran volunteer on Dec. 28, 1863 in Chattanooga, TN. Those Hoosiers who opted to reenlist were awarded a bounty of $402.00 per man and a 30-day furlough home during the months of Jan.-Feb. 1864. Baker was wounded at Buzzard's Roost Pass, GA on May 9, 1864 during the opening stages of Sherman's Atlanta Campaign. He mustered out as a CPL on July 15, 1865 in Louisville, KY - one of very few men who could say they fought with the Thirty-eighth Indiana regiment from its organization at Camp Noble in the fall of 1861 to its final muster out in July 1865.
Joseph applied for a veteran's invalid pension on Nov. 8, 1869 (app. #150,189; cert. #105,175 – Indiana). He passed away in Feb. 1879. His wife Ellen applied for a widow pension Oct. 6, 1880 (app. #278,355; cert. #279,483).