George W. Bush (the 43rd president) is the son of George Bush (the 41st president).
John Quincy Adams (the 6th president) was the son of John Adams (the 2nd president).
Benjamin Harrison (the 23rd president) was the grandson of William Henry Harrison (the 9th president).
James Madison (the 4th president) and Zachary Taylor (the 12th president) were second cousins.
Franklin Delano Roosevelt (the 32nd president) was a fifth cousin of Theodore Roosevelt (the 26th president). Genealogists have determined that FDR was distantly related to a total of 11 U.S. presidents, 5 by blood and 6 by marriage: John Adams, John Quincy Adams, Ulysses Grant, William Henry Harrison, Benjamin Harrison, James Madison, Theodore Roosevelt, William Taft, Zachary Taylor, Martin Van Buren, and George Washington.