What decade does Joseph J Ellis consider the most important in American history and why

I think that would be the Amarican Revolution. 

“No event in American history which was so improbable at the time has seemed so inevitable in retrospect as the American Revolution”

Ellis reminds the reader that though Americans take the fact of their independence for granted, their forefathers were not so certain of revolutionary success. Had certain circumstances favored the British in the war, these forefathers might as easily have been hung for treason as celebrated for victory. Yet these men acted as though there was an air of providence and predestination, and a fortunate combination of luck, intellect, and perseverance served to shape the foundation of the United States. No other colony at that time in history had ever successfully won its independence to form a lasting republic. In fact, the United States remains the oldest surviving republic in history.