Coolest people in American history. I guess whatever your definition of "cool" happens to be is pretty important. Lets take the person in their prime (some people were cool at one point, and got less cool as they got older for one reason or another, so, lets just accept them in their "prime cool years")
Top 4, not necessarily in order.
Johnny Cash
The Fonz
John Wayne
James Dean
Honorable Mention, not necessarily in order: Newman, Elvis, Clooney, Denzel, Rock Hudson, Eastwood, Bronson, Samuel L and of course, LL Cool J
*i didnt google and research this, just off the top of my head*