Here are some Civil War type places I’ve gone to in the past that are worth the time.
Antietam, Sharpsburg, MD
Ford’s Theatre, Washington, DC
Fort Washington, Maryland
Frederick Douglass House, Washington, DC
Gettysburg, Gettysburg, PA
Harpers Ferry, Harpers Ferry, WV
Lincoln Memorial, Washington, DC
Manassas, Manassas, VA
Monacacy, Frederick, MD
Museum of the Confederacy, Richmond, VA
National Museum of Civil War Medicine, Frederick, MD
Robert E. Lee Memorial, Arlington Cemetery, VA
Surratt House, Clinton, MD