4. Ulysses S. Grant Age at inauguration: 46 years, 311 days In office: 1869–1877 The popular Union general served two consecutive terms and was considered by most historians to be a far better general than he was a President. He served 1869–1877. The 15th Amendment became law during his first term; also during this time, the country suffered through a depression. His administration survived the Credit Mobilier scandal and endured a few other scandals in his second term. Grant was also known as trying to reverse decades of persecution toward Native Americans.

3. Bill Clinton Age at inauguration: 48 years, 101 days In office: 1993–2001 Clinton, a Democrat, won the election of 1992, defeating Republican incumbent George Bush and third-party candidate Ross Perot. Clinton was then re-elected in 1996. His time in office was punctuated by internal highs (major welfare reform) and lows (he was impeached but acquitted). Clinton signed into law the North American Free Trade Agreement. As well, for the last three years of his presidency, Clinton oversaw a budget surplus.

2. John F. Kennedy Age at inauguration: 43 years, 236 days In office: 1961–1963 Kennedy won the closely contested Election of 1960 but did not serve out his term. He was assassinated on Nov. 22, 1963. Accomplishments during his three years in office included averting nuclear disaster during the Cuban Missile Crisis, establishment of the Peace Corps, and signing (and convincing the Soviet Union’s leader to sign) a nuclear arms treaty. Not-so-stellar marks on Kennedy’s record included the botched Bay of Pigs invasion and an escalation of military involvement in Southeast Asia.