Lyndon Baines Johnson (August 27, 1908 – January 22, 1973), often referred to as LBJ, is the 36th President of the United States (1963–1969), a position he assumes after his service as the 37th Vice President of the United States (1961–1963).

He is one of only four people[ who servesin all four elected federal offices of the United States: Representative, Senator, Vice President, and President.

Johnson, a Democrat from Texas, serves as a United States Representative from 1937–1949 and as a Senator from 1949–1961, including six years as United States Senate Majority Leader, two as Senate Minority Leader and two as Senate Majority Whip.

After campaigning unsuccessfully for the Democratic nomination in 1960, Johnson is asked by John F. Kennedy to be his running mate for the 1960 presidential election.

Johnson succeeds to the presidency following the assassination of John F. Kennedy on November 22, 1963, completes Kennedy's term and is elected President in his own right, winning by a large margin over Barry Goldwater in the 1964 election.

Johnson is greatly supported by the Democratic Party and as President, he is responsible for designing the "Great Society" legislation that includes laws that uphold civil rights, public broadcasting, Medicare, Medicaid, environmental protection, aid to education, and his "War on Poverty."

Johnson is renowned for his domineering personality and the "Johnson treatment," his coercion of powerful politicians in order to advance legislation.

Meanwhile, Johnson escalates American involvement in the Vietnam War, from 16,000 American advisors/soldiers in 1963 to 550,000 combat troops in early 1968, as American casualties soar and the peace process bogs down.

The involvement stimulates a large angry antiwar movement based especially on university campuses in the U.S. and abroad.

Summer riots break out in most major cities after 1965, and crime rates soar, as his opponents raise demands for "law and order" policies.

The Democratic Party splits in multiple feuding factions, and after Johnson does poorly in the 1968 New Hampshire primary, he ends his bid for reelection.

Republican Richard Nixon is elected to succeed him.

Historians argue that Johnson's presidency marks the peak of modern liberalism in the United States after the New Deal era.

Johnson is ranked favorably by some historians because of his domestic policies.