As America enters the 250th year since the signing of the Declaration of Independence, director Ken Burns tells John Dickerson that the American Revolution was a "civil war" that became a "big world war by the end" and more.

The American Revolution was one of the most significant events in world history because it created a "new thing called a citizen," iconic filmmaker Ken Burns told CBS News, as the nation celebrates the Fourth of July exactly one year before its 250th birthday.