2nd Lt. James H. Day was the son of Richard Day and Elizabeth Penn, the grandson of David Day, Jr. and Stephen Penn. At the time of enlistment into the 1st Alabama Cavalry, US on July 21, 1862, he was 21 years old, 6' 1" tall with light complexion, blue eyes, and sandy hair. He was appointed 4th Sgt. upon organization of the original infantry company, and held rank of sergeant until October 12, 1863 when he was commissioned 2nd Lt. at Camp Davies, MS. He was born in Morgan Co., AL.

On November 1, 1864, 21 men of his company were selected as personal escorts to General Sherman. He took command of the company's remaining 24 men.

On March 10, 1865, he was given command of Company K, after its leader was killed in action in North Carolina. He returned to his company in May and was mustered out with his unit July 19, 1865.

Lt. Day returned to his home community, married Martha Simpson and fathered four children. His first-born, George Spencer Day, was named after Col. George Spencer, the commander of the First Alabama Cavalry. He died January 1, 1881 at the age of 40.