This large stone residence served as a field hospital during the Battle of Gettysburg between stints as a tavern.

This covered bridge was used by both Union and Confederate troops during the Battle of Gettysburg in 1863.

This Civil War monument was designed by an eccentric architect and Gettysburg veteran.

A piece of baseball history is preserved in a Pittsburgh parking lot.

The mounds at this site were reconstructed with the help of archaeologists and historians.

The beloved, war-tested mascot of a Union regiment graces their battlefield monument.

This historic furnace was once used to produce cannonballs during the Civil War.

This outdoor exhibit features a historic wooden dam once used to help boats navigate the Ohio River.

Inside houses a vast collection of military aircraft and missiles spanning the ages.

For decades, this waterfall remained hidden because of an artificial dam.

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.

The site of the little-known Pennsylvania battle that sparked the Seven Years' War.

A bronze monument to Cleveland's favorite, fastest son.

Built by the patriotic residents of Boonsboro in a single day.

The only depiction of Abraham Lincoln holding a weapon, and the names of all 9,000 Cuyahoga veterans of the Civil War.

Cleveland's giant "free" stamp is a nod to the Civil War, but was misinterpreted for years.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

This permanent exhibition celebrates the finest of our heartless automatons both real and fictional.

This lovely university observatory continues to sit abandoned since its potential savior was sent to jail for fraud.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

Steepest flood safety railway in the entire world.

Memorializing an American tragedy of massive proportions.

A real flying saucer, contracted by the U.S. Air Force.