Final answer:
Lyndon B. Johnson, commonly known as LBJ, served as the 36th President of the United States. He focused on civil rights legislation and implemented social programs as part of his vision for the Great Society.
Step-by-step explanation:
Lyndon B. Johnson, commonly known as LBJ, served as the 36th President of the United States. He took office following the assassination of John F. Kennedy in 1963. During his presidency, Johnson focused on civil rights legislation, signing the Civil Rights Act of 1964, which prohibited discrimination based on race, religion, national origin, and gender. He also implemented social programs as part of his vision for the Great Society, including Medicare and Medicaid.