Mr. Obama has said that he is reading up on the two former presidents, who also took office during troubled times in America.
Two authors with new biographies of Lincoln and Roosevelt answered your questions about lessons both Obama and America can learn from the past.
Harold Holzer is the author of "Lincoln: President-elect: Abraham Lincoln and the Great Secession Winter." He's co-chairman of the U.S. Lincoln Bicentennial Commission and the former senior vice president at the Metropolitan Museum in New York.
H.W. Brands is a professor of history at the University of Texas at Austin. He is the author of "Traitor to His Class: The Privileged Life and Radical Presidency of Franklin Delano Roosevelt."