JOHN ADAMS AND HIS WIFE ABIGAIL have become renowned for having a marriage that even modern female historians admire. Abigail spoke her mind and John treated her as his best friend, adviser and lover. Their son, JOHN QUINCY ADAMS, followed in his father's footsteps and was elected president in 1824.

THOMAS JEFFERSON deeply mourned the loss of HIS WIFE, MARTHA. Between their marriage in 1772 and her death in 1782, they lost as many babies as survived, and Thomas was often away. His now-infamous liaison with slave SALLY HEMINGS would have occurred years after Martha's death. Some of his contemporaries and modern historians have speculated that Sally's attraction may have been partly that she was his late wife's half-sister, fathered by Martha's father in a liaison with his slave, Sally's mother. Sally apparently bore a resemblance to Martha.

JAMES BUCHANAN was the only bachelor president. He had fallen in love with a millionaire's daughter in his hometown of Lancaster, Pa., but their relationship failed because of rumors and misunderstandings.

GROVER CLEVELAND was the only president to be married in the White House. His young bride then had a series of children, which also was a novelty for the White House.

BENJAMIN HARRISON was the only grandson of a president ever elected president. His grandfather, WILLIAM HENRY HARRISON, had been the oldest man ever elected president (until Ronald Reagan), the first to die in office and the president to serve the shortest term of office.

THEODORE ROOSEVELT'S second marriage had brought him several children, who were at playful ages when he entered the White House. Thus the nation enjoyed hearing about the children's games and pets, a phenomenon not repeated until the next youngest president to enter office, JOHN F. KENNEDY.

CALVIN COOLIDGE is famous for having taken his oath as president by kerosene lamp light from his own father, a notary public. This was necessary because he took office upon the unexpected death of President WARREN HARDING, when Vice President Coolidge was visiting his Vermont family farmhouse.

FRANKLIN ROOSEVELT was a distant cousin of Theodore's, in an old Hudson River Valley Dutch aristocratic family. Franklin's wife Eleanor was the daughter of Theodore's brother, so the first President Roosevelt was her “Uncle Ted.” Thus ELEANOR ROOSEVELT, so far, is the only first lady who did not change her last name to take on her husband's — because they already had the same last name.

BILL CLINTON is the great-great-grandson of Thomas Jefferson Blythe, who served as a Confederate private in the Civil War.

Only eight presidents had second marriages, the most recent being RONALD REAGAN, who was the first divorced man elected president.