Genealogical relationships of Presidents of the United States

Many genealogical relationships may be found among Presidents of the United States and between the presidents and other significant figures of history.

Direct descent
The United States Presidents who are related to each other by direct descent are:
 * John Adams and John Quincy Adams (father and son)
 * William Henry Harrison and Benjamin Harrison (grandfather and grandson)
 * George H. W. Bush and George W. Bush (father and son)

Two other pairs of Presidents have shared a surname. Andrew Johnson and Lyndon Johnson have no known relationship. Theodore Roosevelt and Franklin Roosevelt were fifth cousins, though they were more closely related through Franklin's wife Eleanor Roosevelt (née Roosevelt), who was Theodore's niece.

Indirect relatives
This is a list of some of the closer blood relations, other than direct descent, between U.S. Presidents. (See Cousin chart to understand the terms used here.)

Second cousins

 * James Madison and Zachary Taylor

Third cousins

 * Martin Van Buren and Theodore Roosevelt (three times removed)
 * Martin Van Buren and Franklin Roosevelt (four times removed)
 * John Adams and Calvin Coolidge (five times removed)
 * James Madison and Barack Obama (nine times removed)

Fourth cousins

 * John Tyler and William Henry Harrison (once removed)
 * Ulysses Grant and Franklin D. Roosevelt (once removed)
 * John Adams and Millard Fillmore (three times removed)
 * John Quincy Adams and Franklin D. Roosevelt (three times removed)
 * Zachary Taylor and Franklin D. Roosevelt (half-cousins, three times removed)
 * James Garfield and George H. W. Bush (three times removed)
 * Lyndon Johnson and Barack Obama (three times removed)
 * John Quincy Adams and Calvin Coolidge (four times removed)
 * Franklin Pierce and Calvin Coolidge (four times removed)
 * James Garfield and George W. Bush (four times removed)
 * John Adams and William Taft (five times removed)
 * Franklin Pierce and Herbert Hoover (five times removed)
 * Millard Fillmore and George H. W. Bush (five times removed)
 * Millard Fillmore and George W. Bush (six times removed)

Fifth cousins

 * Theodore Roosevelt and Franklin Roosevelt
 * Millard Fillmore and Grover Cleveland (once removed)
 * Rutherford Hayes and Grover Cleveland (once removed)
 * John Tyler and Benjamin Harrison (once removed)
 * James Garfield and William Taft (once removed)
 * John Quincy Adams and Millard Fillmore (twice removed)
 * Millard Fillmore and Warren Harding (twice removed)
 * Ulysses Grant and Calvin Coolidge (three times removed)
 * John Quincy Adams and William Taft (four times removed)
 * Millard Fillmore and Herbert Hoover (four times removed)
 * Franklin Pierce and George H. W. Bush (four times removed)
 * Grover Cleveland and Gerald Ford (four times removed)
 * Millard Fillmore and Gerald Ford (five times removed)
 * Franklin Pierce and George W. Bush (five times removed)

Sixth cousins

 * Richard Nixon and Jimmy Carter
 * Millard Fillmore and William Taft (once removed)
 * Ulysses Grant and Grover Cleveland (once removed)
 * Rutherford Hayes and Franklin Roosevelt (once removed)
 * Grover Cleveland and William Taft (once removed)
 * Franklin Pierce and Franklin Roosevelt (twice removed)
 * James Garfield and Calvin Coolidge (twice removed)
 * William Taft and Franklin Roosevelt (twice removed)
 * Calvin Coolidge and Franklin D. Roosevelt (twice removed)
 * Calvin Coolidge and George H. W. Bush (twice removed)
 * Franklin Roosevelt and Gerald Ford (twice removed)
 * Ulysses Grant and Gerald Ford (three times removed)
 * Rutherford Hayes and Gerald Ford (three times removed)
 * Rutherford Hayes and George H. W. Bush (three times removed)
 * William Taft and George H. W. Bush (three times removed)
 * Calvin Coolidge and George W. Bush (three times removed)
 * Franklin Roosevelt and George H. W. Bush (three times removed)
 * Millard Fillmore and Calvin Coolidge (four times removed)
 * Rutherford Hayes and George W. Bush (four times removed)
 * William Taft and George W. Bush (four times removed)
 * Franklin Roosevelt and George W. Bush (four times removed)
 * Ulysses Grant and George H. W. Bush (five times removed)
 * Ulysses Grant and George W. Bush (six times removed)

Seventh cousins

 * Millard Fillmore and Ulysses Grant
 * Benjamin Harrison and William Taft
 * Gerald Ford and George H. W. Bush
 * William Taft and Calvin Coolidge (once removed)
 * Millard Fillmore and Franklin D. Roosevelt (once removed)
 * Gerald Ford and George W. Bush (once removed)
 * Grover Cleveland and George H. W. Bush (twice removed)
 * James Garfield and Richard Nixon (twice removed)
 * William Taft and Richard Nixon (twice removed)
 * William Taft and Gerald Ford (twice removed)
 * James Garfield and Herbert Hoover (three times removed)
 * James Garfield and Gerald Ford (three times removed)
 * Grover Cleveland and George W. Bush (three times removed)
 * Theodore Roosevelt and George H. W. Bush (three times removed)
 * Harry Truman and Barack Obama (three times removed)
 * Abraham Lincoln and Gerald Ford (four times removed)
 * Abraham Lincoln and George H. W. Bush (four times removed)
 * Theodore Roosevelt and George W. Bush (four times removed)
 * Abraham Lincoln and George W. Bush (five times removed)

Eighth cousins

 * Grover Cleveland and Franklin D. Roosevelt (half-cousins)
 * Rutherford B. Hayes and William Taft (once removed)
 * Calvin Coolidge and Herbert Hoover (once removed)
 * Calvin Coolidge and Richard Nixon (once removed)
 * Calvin Coolidge and Gerald Ford (once removed)
 * Herbert Hoover and Gerald Ford (once removed)
 * Franklin Roosevelt and Richard Nixon (once removed)
 * William Taft and Warren Harding (twice removed)
 * Richard Nixon and Gerald Ford (twice removed)
 * Jimmy Carter and Barack Obama (twice removed)
 * Rutherford B. Hayes and Richard Nixon (three times removed)

Ninth cousins

 * Warren Harding and Richard Nixon
 * Warren Harding and Jimmy Carter
 * Benjamin Harrison and Calvin Coolidge (once removed)
 * Warren Harding and Gerald Ford (once removed)
 * Richard Nixon and George H. W. Bush (once removed)
 * Richard Nixon and George W. Bush (twice removed)

Tenth cousins

 * Herbert Hoover and George H. W. Bush
 * Herbert Hoover and George W. Bush (once removed)
 * Gerald Ford and Barack Obama (once removed)
 * George H.W. Bush and Barack Obama (once removed)
 * George W. Bush and Barack Obama (twice removed)

Other relationships
The list above includes the closer, more significant relationships. Family trees, particularly those in a limited geographic area, tend to converge relatively rapidly and many family trees going back ten generations or more will connect to more than one dozen U.S. Presidents, if all female ancestors and their descendants are traced. This is why, for example, it is not mentioned that through Robert Wyngate of Sharpenhoe, Bedfordshire, J.Q. Adams and W.H. Harrison are eighth cousins.

There are also numerous relationships by marriage which are not presented in this article. For example, Richard Nixon was the father-in-law of Dwight Eisenhower's grandson. George Washington's half aunt married James Madison's half great-uncle. Woodrow Wilson married (as his second wife) the great-great-great-niece of Thomas Jefferson.

Presidents related to British royalty

 * George Washington (descendant of Edward III of England)
 * Thomas Jefferson (descendant of Edward III of England)
 * James Madison (descendant of Edward I of England)
 * James Monroe (descendant of Edward III of England)
 * John Quincy Adams (descendant of Edward III of England)
 * William Henry Harrison and his grandson, Benjamin Harrison (descendants of Edward I of England)
 * Zachary Taylor (descendant of Edward I of England)
 * Franklin Pierce (descendant of Henry I of England)
 * Rutherford Hayes (descendant of William I of Scotland)
 * Grover Cleveland (descendant of Edward I of England)
 * Theodore Roosevelt (descendant of James I of Scotland and Edward III of England)
 * William Taft (descendant of Edward III of England)
 * Warren Harding (descendant of Henry II of England)
 * Calvin Coolidge (descendant of Edward I of England)
 * Herbert Hoover (descendant of Edward III of England)
 * Franklin Roosevelt (descendant of James II of Scotland)
 * Harry S. Truman (descendant of Robert III of Scotland)
 * Richard Nixon (descendant of Henry II of England)
 * Gerald Ford (descendant of Edward I of England)
 * Jimmy Carter (descendant of Henry II of England)
 * George H.W. Bush and his son, George W. Bush (descendants of Edward I of England and Robert II of Scotland)
 * Barack Obama (descendant of Edward I of England and William the Lion of Scotland)

As a result, all of the listed people are direct descendants of Alfred the Great. All but one of them are also descended from William the Conqueror with the exception of Rutherford Hayes. Most of these royal ancestors were born before the Black Death killed much of the population of Britain in 1349.

In addition, according to Genealogics and Roglo, HM Queen Elizabeth II is among the closest living relatives of George Washington, through their descent from Augustus Warner, Burgess of Virginia.

Presidents related to other royalty

 * Theodore Roosevelt and Franklin Roosevelt are related to the Rajahs of Sarawak