Wait - an american knew we had a Prime Minister and not a President?
!
So, George Washington, Thomas Jefferson, John Adams, John Q. Adams, Andrew Jackson, James Madison, William Harrison, John Tyler, something Van Buren, Abraham Lincoln, Ullyses Grant, William McKinley, Teddy Roosevelt, Herbert Hoover, Calvin Coolidge, Franklin Delano Roosevelt, Harry Truman, Dwight Eisenhower, Richard Nixon, John F Kennedy, Jimmy Carter, Gerald Ford, Ronald Reagan, George HW Bush, Bill Clinton, George W Bush, ...
I dont know the rest, but as a Canadian...
John A Mac, Alexander Mackenzie, John A again, some people I forgot, Charles Tupper, Wilfrid Laurier, Robert Borden, Arthur Meighen, William Lyon Mackenzie King, Meighen again, King again, Bennett, King AGAIN, St. Laurent, Diefenbaker, Lester Bowles Pearson, Pierre Elliot Trudeau, Joe Clark, Trudeau take 2, Mulroney, Kim Campbell (look, a woman!), Jean Chretien, Paul Martin, Stephen Harper,
JACK LAYTON
EDIT: and I forgot Sir John Abbott, Sir John Thompson, and Sir Mackenzie Bowell, the 3 of whom were in power for a combined 5 years (1891-1896)