He was famous for discovering the real orbit of the planets and many others
The Bill of Rights contains the first ten amendments to the US Constitution.
The AFL was a formal federation of labor unions whereas the Knights of labor was much more of a secretive type.
the Eiffel Tower was built to to commemorate the hundred year anniversary of the French Revolution. It was also supposed to be a temporary structure, but due to its odd shape and popularity, they didn't destroy it.