The museum comprises two galleries that chronicle the history of Wisconsin citizens who served in the U.S. military from the American Civil War to the present day.

The museum dates to 1901, when it was established as the Grand Army of the Republic Memorial Hall in the Wisconsin State Capitol.

It includes a large diorama depicting the Battle of Antietam.

In the 20th-century gallery, exhibits illustrate Wisconsin veterans' roles in the Mexican Border campaign, the First and Second World Wars and also the Korean, Vietnam, Persian Gulf War and recent conflicts.

Additions include Medal of Honor and War on Terror exhibits.