Based purely on their significance (how they changed things in ways other men may not have done so) ....
1. FDR - 12 years as President gives you a lot of time to make changes. His social programs and foreign intervention changed America and the world as a whole.
2. Thomas Jefferson - 2 words, Louisiana Purchase (literally doubled the size of the country). 2 more words, West Point (gave America its own training center for a professional army).
3. Abe Lincoln - Some men would have let the nation split. Some men would not have excercised emmancipation. Like him or not, he changed the nation.
4. LBJ - Great Society, escalation of Vietnam, civil rights. During LBJ America grew up.
I think you need to reread the question.
