James D. Phillips of the 42nd Mississippi, according to Confederate Military History, Extended Addition, Tennessee, vol. X, pp. 671-672 (cited below), was born in McMinnville, Tennessee in 1834, and was mortally wounded while carrying the regimental colors of the 42nd Mississippi on July 3.
https://archive.org/details/confederatemilit0000unse_n0k1/page/670/mode/2up
However, Phillips' service records (Fold3, posted above) reflect that he was 23 years of age as of May 1862 and had been born in Mississippi.
It would certainly be helpful to resolve the conflicting data as I had previously cited him as a color bearer at Gettysburg:
Color Sgt Gillian Ryerson 7th NJ After the failed assault at Petersburg on June 18, 1864, the 7th along with others threw up earthworks near the Hare House. Ryerson placed the National Colors on the works, daring the rebels to shoot it down. When a shot shattered the staff, knocking the Colors...
civilwartalk.com
I am thinking his service records reflect when he arrived in Mississippi (ca. 1839) from Tennessee, when he would actually have been about five years old.
If the Tennessee connection holds up, your ancestor not only fought in one of the decisive battles of the war, but also demonstrated heroic valor unto death while carrying a regimental banner into one of the most epic charges in recorded history. Something to be immensely proud of, for sure.