Lyndon Baines Johnson, often referred to by his initials LBJ, was an American politician who served as the 36th president of the United States from 1963 to 1969. He became president after the assassination of John F. Kennedy, under whom he had served as the 37th vice president from 1961 to 1963. A Democrat from Texas, Johnson also served as a U.S. representative and U.S. senator.

The vice president of the United States (VPOTUS) is the second-highest officer in the executive branch of the U.S. federal government, after the president of the United States, and ranks first in the presidential line of succession. The vice president is also an officer in the legislative branch, as the president of the Senate. In this capacity, the vice president is empowered to preside over the United States Senate, but may not vote except to cast a tie-breaking vote. The vice president is indirectly elected together with the president to a four-year term of office by the people of the United States through the Electoral College. Since the passage of the Twenty-fifth Amendment to the US Constitution, the vice president may also be appointed by the president to fill a vacancy, via majority confirmation by both the Senate and the House.