We don't see many soldiers from Ft. Jackson wanting to register, so the Army must inform them ahead of time about how they can vote. We might occasionally run into someone who will be traveling or working overseas, so they can click here for many details about doing this. Below are a few general points for them from the Uniformed and Overseas Citizens Absentee Voting Act (UOCAVA). The Act applies to all who are traveling at election time, serving in the military, and working for the US or Red Cross or USO in other countries.
Voters must submit a Federal Post Card Application (FPCA), obtained from the FPCA website. That will tell them how to receive and return a ballot.
The deadline for returning these BALLOTS is election day.