Lyndon Baines Johnson, 36th president of the United States, assumed office following the assassination of President Kennedy, on November 22, 1963. The tall, booming voice of Texas entered the presidency with a reputation for political expertise. Now the highest elected office in the land, LBJ was eager to make use of his legislative knowledge. With Kennedy assassinated, LBJ inherited a number of unresolved bills, including a civil rights bill.

In 1964, after a difficult passage through the Senate, LBJ signed the Civil Rights Bill that outlawed segregation in public facilities and employment. In 1965, the Voting Rights Bill, which protected voting rights for African Americans, was also passed. LBJ's "Great Society" was a major undertaking to eliminate poverty and expand opportunities for all Americans. Medicare and Medicaid programs were established to provide medical insurance to the elderly and poor people respectively. Funding was provided for the education of children in poor areas. The Department of Housing and Urban Development was created and a Head Start program was launched. Poverty declined and the unemployment rate fell throughout most of his presidency. Johnson's social programs represented the most significant legislation passed since Franklin Roosevelt's New Deal and changed the landscape of American politics.

On the issue of Vietnam, Johnson escalated the war and increased the number of troops sent there. After reported attacks in the Gulf of Tonkin, in 1964, Congress granted the president expanded powers to take military actions. By 1968, over 500,000 troops were stationed in Vietnam as the war escalated and became increasingly unpopular. The Tet Offensive was reported in early 1968 and, even though it was described as a military failure for the enemy, it caused the American public to lose faith in the war. In March 1968, Johnson announced that he would not run for re-election. He spent his last months trying to start peace talks in Paris, but progress came slowly. LBJ left the presidency in January 1969, succeeded by Richard Nixon.

LBJ died in 1973 but his legacy lives on in the laws he championed and the problems he left unresolved. His legacy is a complicated one: he pushed through significant social legislation to assist the needy and end institutional racism, but the war in Vietnam cost lives and led to a sharp division in the American electorate. His policies remain a point of debate among Americans today. In many ways, LBJ embodied the belief of the mid-20th century that government has the power to solve any of society's problems. His actions demonstrated that it could.