The ironworks building has been remodeled into a meeting center, but the exterior is still of some interest. The US Army infantry museum is located well inside Fort Benning, just south of Columbus. It has an extensive array of exhibits covering Army history from the American Revolution to Gulf Storm in a three-storied building. Over the years the museum has accumulated a lot of stuff, and they're trying to present as much as possible. There's a nice assembly of vehicles out in front.
Admission is free.
The drive down from Columbus is a little tricky, and watch the signs on Fort Benning very carefully. This museum is located in its own building near the Columbus convention center at the south end of Veterans Parkway. The main attractions are a number of very nice models and the remains of the Confederate boats Chatahoochie and the Jackson . There is also a Civil War naval museum located in Vicksburg. The Confederate navy is an obscure area of the war.