This one-room cabin where the young colonel slept during the French and Indian War.

The first blast furnace in the United States that used coal and coke fuel instead of charcoal to make pig iron.

Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

This monument traces the segregation line that inspired the first rural branch of the NAACP.

A whopping 14,000 copper coins cover this miniature fighter jet.

An eponymous directional signpost erected by the first president of the United States.

A natural spring situated on the grounds of the Hawthorne estate.

For nearly a year, General Ulysses S. Grant was based here during the American Civil War.

This train station inspired the name of a 1970's rock band and provided the backdrop for their album cover.

America's first federal monument.

The narrowest house in America is seven feet of pure spite.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

Look closely and you’ll notice that the color changes a third of the way up the tower.