Title: List of presidents of the United States by age
Content:  F. Kennedy was the youngest president at the end of his tenure, and his lifespan was the shortest of any president. At age 50, Theodore Roosevelt was the youngest person to become a former president. The oldest president at the end of his tenure was Ronald Reagan at 77; this distinction will eventually devolve upon Joe Biden, who was older when he took office than Reagan was when he left office. The president born after the greatest number of his successors is John F. Kennedy. He was born after four of his successors: Lyndon B. Johnson (8 years, 9 months, 7 days); Ronald Reagan (6 years, 3 months, 24 days); 
Title: List of presidents of the United States by age
Content:  The median age at inauguration of incoming U.S. presidents is 55 years. The specific years and days median is 55 years and 355 days, which falls midway between how old Grover Cleveland was in 1893 and Richard Nixon was in 1969. The youngest person to assume the presidency was Theodore Roosevelt, who, at the age of 42, succeeded to the office after the assassination of William McKinley. The youngest to become president by election was John F. Kennedy, who was inaugurated at age 43. The oldest person to assume the presidency was Joe Biden, who took the presidential oath of office two months after turning 78. Assassinated at age 46, 
Title: 1988 United States presidential election
Content:  over 33 years after his first campaign for the office ended.) Al Gore, a Senator from Tennessee, also chose to run for the nomination. Turning 40 in 1988, he would have been the youngest man to contest the presidency on a major party ticket since William Jennings Bryan in 1896, and the youngest president ever if elected, younger than John F. Kennedy at election age and Theodore Roosevelt at age of assumption of office. He eventually became the 45th Vice President of the United States under Bill Clinton, then the Democratic presidential nominee in 2000, losing to George W. Bush, George H.W.'s son.
Title: 1960 United States presidential election
Content:  years, 11 days, he would have been the fourth-youngest president at the date of inauguration. Kennedy, by contrast, was 43 years, 236 days, on the date of his inauguration; the second-youngest man to begin a Presidency. (At 42 Theodore Roosevelt, who assumed the Presidency upon the assassination of United States President William McKinley 60 years previously, was (and remains) the youngest.) During Kennedy's campaign, he relied on his youth and promised to bring about change. Kennedy had a slogan emphasizing his youth, reading, "who's seasoned through and through/but not so dog-gone seasoned that he won't try something new". He was also endorsed by celebrities such as Frank Sinatra, Henry Fonda, and Harry Belafonte. Nixon asserted that his experience in politics made him more qualified to hold the office of president. He wanted voters to know that he had the abilities to take on Communist threats.
Title: List of youngest members of the United States Congress
Content:  political culture of the United States encourages young politicians to gain experience in state and local offices before running for Congress. Although the vast majority of members of Congress gained state and local experience before being elected to Congress, members lacking state and local experience have increased recently. Madison Cawthorn (R-NC) is the youngest member of the 117th Congress at age 26. He replaced Alexandria Ocasio-Cortez (D-NY), who is the youngest woman ever elected to Congress and was the youngest of the 116th Congress. Cawthorn is the youngest person elected to the U.S. Congress since Jed Johnson Jr. in 1964. Jon Ossoff (D-GA) is the 
Title: Age of candidacy
Content:  1964 Congressman Jed Johnson Jr. of Oklahoma was elected to the 89th Congress in the 1964 election while still aged 24 years. However, he became eligible for the House after turning 25 on his birthday, 27 December 1964, seven days before his swearing in, making him the youngest legally elected and seated member of the United States Congress. In South Carolina, two Senators aged 24 were elected, but were too young according to the State Constitution: Mike Laughlin in 1969 and Bryan Dorn (later a U.S. congressman) in 1941. They were seated anyway. On several occasions, the Socialist Workers Party (USA) has nominated 
Title: List of vice presidents of the United States by age
Content:  The median age upon accession to the vice presidency is around 54 years and 10 months. This is about how old John Adams and Hubert Humphrey were at the time they entered office. The youngest person to assume office was John C. Breckinridge, at the age of 36 years, 56 days. Serving only one term, he became and remains the youngest at the time of leaving office; the oldest at the time of entering office was Alben W. Barkley, at the age of 71 years, 74 days. He was also the oldest when he left office. Born on January 16, 1821, John C. Breckinridge was younger than five of his successors, the greatest number to date: Andrew Johnson (12 years, 21 days); Hannibal Hamlin (11 years, 4 
Title: List of youngest members of the United States Congress
Content:  sitting senator at 35, replacing Missouri Senator Josh Hawley, who at 41 was the youngest senator of the 116th Congress. Ossoff is the youngest person elected to the U.S. Senate since Don Nickles in 1980. The average age of senators is now higher than in the past. In the 19th century, several state legislatures elected senators in their late twenties despite the Constitutional minimum age of 30, such as Henry Clay, who was sworn into office at age 29, and John Henry Eaton, the youngest US Senator in history, who took his oath of office when he was 28 years, 5 months, 7 days old.
Title: Baby of the House
Content:  aiming to serve in the federal legislature generally seek election to the state legislature (which generally have lower minimum ages for entry) or other state office before seeking to serve in Washington. In the 117th Congress, which began on 3 January 2021, the youngest member of the United States House of Representatives is Madison Cawthorn, who was born on August 1, 1995, and was first elected in 2020 three months after his 25th birthday. He replaced Alexandria Ocasio-Cortez, the youngest woman elected to the House in U.S. history. Currently the youngest US Senator is Jon Ossoff, born on February 16, 1987, and first elected to a full term in the Senate in the 2020–21 United States Senate election in Georgia.
Title: Presidency of John F. Kennedy
Content:  On November 8, 1960, Kennedy defeated Nixon in one of the closest presidential elections of the 20th century. Kennedy won the popular vote by a narrow margin of 120,000 votes out of a record 68.8 million ballots cast. He won the electoral vote by a wider margin, receiving 303 votes to Nixon's 219. 14 unpledged electors from two states—Alabama and Mississippi—voted for Senator Harry F. Byrd of Virginia, as did one faithless elector in Oklahoma. In the concurrent congressional elections, Democrats retained wide majorities in both the House of Representatives and the Senate. Kennedy was the first person born in the 20th century to be elected president, and, at age 43, the youngest person elected to the office. He was also the first Roman Catholic elected to the presidency.

Question: who was the youngest president to be elected?
Answer: Theodore Roosevelt.
John F. Kennedy.