There's quite a bit of information on John L. Foster at the Fold3 website. He enlisted October 14 1861 for three years. He was 24 years old, 6 foot one inches tall, had blue eyes and fair hair. He was born in Bullitt County, Kentucky and worked as a farmer at the time of enlistment. He evidently enlisted as a private but began acting as sergeant almost immediately and was promoted to 2nd lieutenant in October of 1862. He was wounded at Chaplin Hills/Perryville and left in the hospital that same month. He was back with his company by April of 1863. A note says he resigned in October of 1863 but the muster roll for November/December of 1863 still has him listed. It does note he was "In charge of convalescent barracks" so he may have been too ill or wounded to serve fully. In February of 1864 he was promoted to 1st lieutenant. A note on the January/February 1864 muster roll says "been in charge of company since Oct 26/63" and in March of 1864 he is promoted to captain. The May/June 1864 muster roll notes he was sick in the officers hospital in Chattanooga. The last timeline information is that he was present through November 1864.