I think there's a biography of Geo. Washington entitled "The Indispensible Man." I'll concur with you; Washington is key. If it weren't for him, there wouldn't have been a Lincoln or a Reagan...the nation itself might not have survived into the 19th Century. And I'd put Lincoln second. He saved the union, the "last, best hope" of the world, assuring that the experiment in republican government would succeed, moving the nation to fulfill it's original promise in a "new birth of freedom." Reagan is right up there, because when you consider the abysmal condition of the nation in the '70s, it's amazing that he was elected in the first place, and he went on to transform American politics, not to mention winning the Cold War.
Washington - Lincoln - Reagan. They're all indispensible men, in all honesty.
That is the name of one of his bigraphies...by Freeman, who also wrote a 7-volume bio of the General. He not only was the key for the Revolution, but he set the tone for the Presidency and the country with his courage, honesty, class, intelligence and compassion (among other things). There was no other like him.
Best,
PB