Johnson was born in 1908 in Stonewall, Texas, as the oldest of five children. Though his father had served in the state legislature, he had lost money in cotton speculation, and the family often struggled to make ends meet. The young Johnson drifted for a few years after high school but enrolled at Southwest Texas State Teachers College in 1927. During his time there, he taught in a largely Mexican-American school in the south Texas town of Cotulla, where he was known for his energy, dedication and encouragement of his underprivileged students. Though Johnson would soon turn his attention to politics, heading to Washington as a congressional aide in 1931, his experience as a teacher left a lasting impression.

Johnson worked hard and rose quickly, winning a special election to the U.S. House of Representatives in 1937 when a congressman in his district died in office. In 1941, he ran for U.S. Senate in another special election but lost. He tried again in 1948, squaring off against the popular Texas governor Coke Stevenson in the Democratic primary. (At the time, there were so few Republicans in Texas that winning the primary basically meant getting elected.) In a race that was rife with voter fraud on both sides, Johnson won by a razor-thin margin, earning the derisive nickname “Landslide Lyndon.”

In 1953, Johnson became Senate minority leader, and after Democrats regained control of the Senate two years later, he became majority leader. Johnson excelled at forming the Senate Democrats into a united bloc, while charming, flattering and otherwise convincing colleagues from both sides of the aisle. In mid-1955, the 49-year-old suffered a severe heart attack; he later described it as “the worst a man could have and still live.” Upon recovery, he quit smoking, lost weight and learned to delegate some responsibilities but he continued in tireless pursuit of his agendas, including civil rights and the U.S. space program.

After losing a bitter primary fight in 1960, Johnson shocked nearly everyone by signing on as running mate to Sen. John F. Kennedy of Massachusetts. As a Protestant Southerner and the consummate insider in Congress, Johnson balanced the ticket, helping Kennedy capture Texas, Louisiana and the Carolinas in his narrow defeat of Richard Nixon. But Johnson’s influence was limited as vice president, as Kennedy’s advisers (especially his brother and attorney general Robert Kennedy) made sure to keep him on the sidelines. During the Cuban Missile Crisis, for example, Johnson was a member of the group convened to advise the president, but was excluded from the meeting at which the final decision about the American response was made.

Everything changed on November 22, 1963, when Kennedy was assassinated in Dallas. Though seven U.S. presidential transitions had happened due to death rather than election, including three assassinations, no president had ever died so late in his term. When Air Force One landed in Washington that night (Johnson had been sworn in aboard), the new president gave a brief speech, saying “I will do my best—that is all I can do.” In the days to come, Johnson worked to calm the national hysteria and took firm control of the government, even as he kept Kennedy’s cabinet and top aides to provide continuity.

On November 27, 1963, Lyndon B. Johnson addressed a joint session of Congress, calling on them to honor the martyred Kennedy’s memory by passing the major civil rights bill that was currently stalled in congressional committees. While preparing his speech, Johnson’s aides had warned him that the bill was most likely a lost cause, and pursuing it would hurt his chances in the next election, less than a year later. Johnson’s simple response—“Well, what the hell’s the presidency for?”—would go down as one of the most famous quotes of his career.

Barely seven months after addressing Congress, Johnson would sign the Civil Rights Act of 1964, which prohibited discrimination on the basis of race, color, religion, sex or national origin, banned segregation and provided for the integration of schools and other public facilities. That Johnson was the president to pass such a historic bill seemed ironic: As a congressman, he voted against every single civil rights bill that ever made it to the floor between 1937 and 1956. Johnson reversed that record with a bang in 1957, pushing through the first civil rights bill to pass Congress since 1875. He passed another one in 1960, but both bills were relatively weak compared to the far-reaching powers of the 1964 act. Even more paradoxically, as a Southern man of his time, Johnson used racist language–even as he smashed Jim Crow laws across the South.

In his first State of the Union address, Johnson declared an “unconditional war” on poverty in the United States, announcing that “Our aim is not only to relieve the symptoms of poverty, but to cure it and, above all, to prevent it.” He spearheaded legislation creating Medicare and Medicaid, expanding Social Security, making the food stamps program permanent and establishing Job Corps, the VISTA program, the federal work-study program, the Head Start program and Title I subsidies for poor school districts. Though the war on poverty is still far from being won, the programs put in place as part of Johnson’s “Great Society” did succeed in reducing economic hardships for millions of Americans, and many are still in place today.

Claudia Alta Taylor, known as Lady Bird from childhood, married Johnson shortly after graduating from the University of Texas at Austin, where she studied history and journalism. She became an undeniable asset to his rising political career, not least because of her considerable family fortune. In 1960, Lady Bird Johnson traveled some 30,000 miles on the campaign trail, and Bobby Kennedy would credit her with winning Texas for the Democratic ticket. Four years later, after her husband had angered Southern voters by signing the Civil Rights Act, she won many of them back with a special train tour, dubbed the “Lady Bird Special.” (Johnson ended up defeating his Republican rival, Barry Goldwater, by one of the largest margins in history.) As first lady, Lady Bird championed the Head Start education program, as well as an environmental initiative aimed at the “beautification” of highways, neighborhoods and parks.

Despite his considerable achievements in the domestic arena, Johnson’s presidency was undeniably marred by the Vietnam War. Despite campaign promises not to widen U.S. involvement in the conflict, which had begun during President Dwight D. Eisenhower’s administration and intensified under Kennedy, Johnson vastly increased the number of U.S. troops in Vietnam and expanded their mission.

By 1967, Johnson’s popularity had plummeted, while the massive cost of war threatened his Great Society programs and spurred inflation. With student demonstrators around the country chanting things like “Hey, hey, LBJ, how many kids did you kill today?” Johnson was plagued with doubt about the war and reportedly fell into a prolonged depression. In March 1968, he announced he would not be seeking reelection. After his VP Hubert Humphrey lost a close race to Richard Nixon, Johnson retired to his beloved Texas ranch in 1969. By that time, some 30,000 American soldiers had been killed in Vietnam. Johnson wouldn’t live to see the official end to that conflict: He died in January 1973, after suffering another heart attack.