President Lyndon B. Johnson played a significant role in Black history with his leadership and involvement in the Civil Rights Movement. Johnson became President after the assassination of John F. Kennedy in 1963 and he continued Kennedy's commitment to advancing civil rights legislation.

In 1964, President Johnson signed the Civil Rights Act into law, which is considered one of the most important pieces of civil rights legislation in American history. The act outlawed discrimination based on race, color, religion, sex, or national origin, and ended segregation in public places. Johnson's support and advocacy were crucial in getting this landmark legislation passed.

Johnson also signed the Voting Rights Act into law in 1965, which aimed to overcome legal barriers at the state and local levels that prevented African Americans from exercising their right to vote as guaranteed by the 15th Amendment. This act played a significant role in increasing African American voter registration and political participation.

Despite his successes in advancing civil rights legislation, Johnson's presidency was also marked by the escalation of the Vietnam War, which overshadowed some of his domestic achievements. However, his contributions to the Civil Rights Movement and his efforts to combat racial discrimination have left a lasting impact on Black history in the United States.