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.

"I think the American Revolution is the most important event since the birth of Christ in all of world history. … I mean, it turned the world upside down," Burns told CBS News' John Dickerson in an interview set to air on "Face the Nation with Margaret Brennan" on Sunday.