US History - Presidents and Leaders: George Washington (1789-1797), America's first president, established many precedents still followed today. Thomas Jefferson (1801-1809) authored the Declaration of Independence and made the Louisiana Purchase. Abraham Lincoln (1861-1865) led the nation through the Civil War and abolished slavery. Franklin D. Roosevelt (1933-1945) served an unprecedented four terms, guiding the country through the Great Depression and World War II. John F. Kennedy (1961-1963) navigated the Cuban Missile Crisis and championed civil rights. Ronald Reagan (1981-1989) is known for his economic policies and role in ending the Cold War.