The first president to get married while in office was John Tyler. John Tyler was also the first president to have his wife die while in office.
Barack Obama was married before he ran for president.
Lincoln got married on November 4, 1842, 18 years beforehe was elected president in November 1860.
Because she is married to the president.
The daughter will.
Get married
James Buchanan
Grover Cleveland
Abigail Fillmore, wife of Millard Fillmore (the 13th President) , was probably the first woman who had a paying job and married a future President.
Ronald Regan Hubert Hoover was the first preisdent to get married in term.
She is the wife of the president or the official White House hostess if the president is not married. ( Michele Obama is the first lady at this date in 2011.)
The first President born in the United States was George Washington, and the only President never to marry was James Buchanan, the 15th President of the United States. A link can be found below.