|courtesy of SoilSister|
Although he was apparently known as Andrew in the family he enlisted as Thomas A. Jackson. He enlisted in the 2nd Virginia Volunteer Infantry on 3 Jun 1917. When the unit was reorganized with others to form the 116th Infantry he was assigned to F Company 116th Infantry. He shipped with that unit for France aboard the Finland on 13 Jun 1918. We do not know when he was wounded but it was most likely in the action at Molleville Farm sometime between 12 and 25 Oct 1918. Evacuated to the hospital he remained there until dying of either his wound(s) or disease (possibly influenza) on 4 Jan 1919.
PFC Jackson was buried in the Meuse-Argonne American Cemetery.
You might note that the year of death on his marker is incorrect. It is not the first or last time the Army has made a clerical error.