King was born on January 15, 1929, at his family's home on Auburn Avenue in Atlanta, Georgia.¹¹ He was the second of three children born to Michael King Sr., a Baptist pastor, and Alberta Williams King, a former schoolteacher.¹² Both his father and his maternal grandfather, Adam Daniel Williams, served as pastors of Atlanta's Ebenezer Baptist Church.¹³ His father later changed both his own name and his son's name from Michael to Martin Luther. Growing up in Atlanta's prosperous Sweet Auburn neighborhood, King witnessed his father stand up against racial segregation, including leading a 1936 march of several hundred African Americans to Atlanta's city hall to protest voting rights discrimination.

Educated in Georgia's segregated public schools, King developed a reputation on his high school debate team for public speaking before leaving high school at age 15 to enter Morehouse College, an all-male historically Black institution in Atlanta. At Morehouse, he was mentored by the college's president, Benjamin Elijah Mays, an outspoken advocate of racial equality and Christian social responsibility who influenced King's decision to enter the ministry.¹⁴ King graduated from Morehouse in 1948 with a Bachelor of Arts degree in sociology.

Later in 1948, King enrolled at Crozer Theological Seminary in Pennsylvania, where he was elected president of his predominantly white senior class, won a graduate fellowship, and earned a Bachelor of Divinity degree in 1951. Beginning in 1951, he pursued doctoral studies in systematic theology at Boston University, completing his coursework in 1953 and receiving his Doctor of Philosophy degree in 1955 with a dissertation titled "A Comparison of the Conceptions of God in the Thinking of Paul Tillich and Henry Nelson Wieman".¹⁵ While studying in Boston, he met Coretta Scott, an Alabama native studying voice and piano at the New England Conservatory of Music.¹⁶ They married on June 18, 1953, on the lawn of her parents' home in Heiberger, Alabama, and subsequently had four children: Yolanda Denise (born 1955), Martin Luther III (born 1957), Dexter Scott (born 1961), and Bernice Albertine (born 1963).¹⁷¹⁸

In September 1954, at age 25, King became the full-time pastor of the Dexter Avenue Baptist Church in Montgomery, Alabama. On December 1, 1955, Rosa Parks, secretary of the local chapter of the National Association for the Advancement of Colored People (NAACP), was arrested for refusing to give up her seat to a white passenger on a segregated Montgomery city bus.¹⁹ Local activists formed the Montgomery Improvement Association to organize a boycott of the municipal transit system and elected King as its president and official spokesman.

The Montgomery bus boycott lasted 382 days, placing severe economic strain on the public transit system. During the campaign, King was arrested, subjected to personal abuse, and had his home bombed in early 1956 while his wife and infant daughter were inside. The boycott concluded on December 21, 1956, after the Supreme Court of the United States ruled that Alabama's laws requiring racial segregation on buses were unconstitutional. The campaign established King as a national civil rights leader and demonstrated the effectiveness of mass nonviolent protest across the South.

In 1957, King, Ralph Abernathy, Fred Shuttlesworth, and other civil rights activists founded the Southern Christian Leadership Conference (SCLC) to coordinate nonviolent direct action for civil rights across southern communities. Elected as the organization's first president, King traveled extensively across the country delivering speeches and organizing protests. In September 1958, while signing copies of his book in New York City, he survived a near-fatal stabbing by a mentally ill woman. In 1960, King and his family relocated from Montgomery back to Atlanta, where he served alongside his father as co-pastor of Ebenezer Baptist Church until his death, allowing him to devote more time to SCLC campaigns.

King's philosophy of social change synthesized the Christian ethic of love with the methods of nonviolent resistance developed by Indian leader Mohandas K. Gandhi. Although King had initially doubted the practicality of nonviolence against entrenched oppression, his view shifted during his time at Crozer Theological Seminary.²⁰²¹ In 1950, after hearing Howard University president Mordecai Johnson lecture on his recent trip to India and Gandhi's satyagraha ("soul force") campaigns, King purchased several books on Gandhi's life and thought.

King came to view Gandhian nonviolence as the only morally and practically sound method available to oppressed people seeking freedom. He frequently summarized this synthesis by stating that Jesus Christ provided the spirit and motivation while Gandhi provided the operational method. Alongside advisers such as Bayard Rustin and James Lawson, who had studied Gandhian tactics firsthand, King applied nonviolent discipline during the Montgomery bus boycott.

In February 1959, King, Coretta Scott King, and historian Lawrence D. Reddick traveled to India for a five-week visit co-sponsored by the American Friends Service Committee and the Gandhi Smarak Nidhi. Hosted by Prime Minister Jawaharlal Nehru, King met with members of Gandhi's family, Indian activists, and students from communities formerly classified as "untouchables". The journey deepened his conviction that nonviolent direct action could compel a democratic majority to confront and dismantle systemic racial injustice in the United States. Throughout his career, King was arrested 30 times for his participation in nonviolent civil rights demonstrations.

In December 1961, King and the SCLC joined local leaders, the Student Nonviolent Coordinating Committee (SNCC), and the NAACP in the Albany Movement, a broad desegregation and voters' rights coalition in Albany, Georgia. Although mass marches and arrests drew national notice, tensions emerged between SNCC organizers—who favored long-term, grassroots democratic organizing—and the SCLC's shorter-term campaigns, and the Albany effort ended without securing immediate concessions from local authorities.

Following the legislative victories in the South, King turned his attention to de facto racial segregation and economic inequality in northern cities.³⁰³¹ Invited by Al Raby's Coordinating Council of Community Organizations (CCCO), King and the SCLC launched the Chicago Freedom Movement in January 1966, with King moving into a dilapidated apartment on Chicago's West Side to highlight slum conditions.³² During the summer of 1966, the coalition conducted "Open City" marches into all-white Chicago neighborhoods to protest housing discrimination.³³ On August 5, 1966, during an open-housing march in Marquette Park on the city's Southwest Side, white mobs hurled bottles and bricks and set demonstrators' cars on fire; King was struck in the head by a rock and remarked that he had "never seen as much hatred and hostility on the part of so many people". On August 26, King and local leaders negotiated a Summit Agreement with Mayor Richard J. Daley and the Chicago Real Estate Board, halting marches—including a planned demonstration into the hostile suburb of Cicero—in exchange for open-housing pledges and the creation of the Leadership Council for Metropolitan Open Communities.

As urban riots broke out across major American cities between 1964 and 1967, and as funding for President Johnson's Great Society anti-poverty programs was diverted to the escalating conflict in Southeast Asia, King increasingly linked racism to economic exploitation and militarism.³⁴³⁵ On April 4, 1967, speaking at Riverside Church in New York City, King officially joined the anti-war movement and publicly denounced the Vietnam War, calling the United States government "the greatest purveyor of violence in the world today".³⁶ His stance alienated many moderate civil rights allies, labor leaders, and the Johnson administration, who objected to merging the civil rights and peace movements. King argued that American society required a fundamental "revolution of values" to defeat the triple evils of racism, poverty, and militarism.

In late 1967, at the suggestion of NAACP Legal Defense Fund attorney Marian Wright, King and the SCLC announced the Poor People's Campaign.³⁷ Seeking a nonviolent alternative between urban riots and passive supplication, King organized a multiracial coalition of African American, Native American, Mexican American, Puerto Rican, and poor white communities to march on Washington, D.C.. The campaign called for an "economic bill of rights" backed by a $30 billion federal anti-poverty package guaranteeing full employment, a guaranteed annual income, and the construction of low-income housing.

Throughout the 1960s, King was the subject of intensive, covert surveillance and harassment by the Federal Bureau of Investigation (FBI) under Director J. Edgar Hoover.³⁸ In October 1962, with authorization from the Attorney General, the FBI opened a security investigation into King and the SCLC, purportedly to investigate potential Communist influence within the organization.³⁹ Following the August 1963 March on Washington, FBI Deputy Director William Sullivan wrote in a September 25, 1963, memorandum that King was "the most dangerous and effective Negro in the country".

Under its domestic counterintelligence program, COINTELPRO, the FBI wiretapped King's telephones, placed hidden microphones in his hotel rooms, and employed informants to gather personal information in an effort to discredit him and dismantle his leadership of the civil rights movement. In late 1964, the bureau sent King an anonymous package containing audio recordings from hotel surveillance along with a letter designed to prompt him to commit suicide. Subsequent congressional investigations, including the 1976 Senate Church Committee and the late-1970s House Select Committee on Assassinations (HSCA), concluded that no evidence existed that King was ever affiliated with the Communist Party, and determined that the FBI had grossly abused and exceeded its legal authority in its campaign against him.⁴⁰

More than two decades after King's death, historians led by Stanford University professor Clayborne Carson, whom Coretta Scott King had appointed to edit King's papers, discovered that portions of King's 1955 Boston University doctoral dissertation contained unattributed material from other scholars.⁴¹ Following a year-long investigation, a committee of scholars appointed by Boston University reported on October 10, 1991, that King had plagiarized passages by appropriating material not explicitly credited in footnotes.⁴² However, the panel concluded that the dissertation still made an intelligent contribution to scholarship, ruled that revoking the degree of a deceased person would serve no academic purpose, and placed a letter noting its findings alongside the official copy of the dissertation in the university library.

In late March 1968, while preparing for the Poor People's Campaign, King traveled to Memphis, Tennessee, to support African American sanitation workers who were striking for higher wages, union recognition, and safer working conditions. On the night of April 3, 1968, King delivered his final address, known as the "I've Been to the Mountaintop" speech, at Mason Temple. The following evening, April 4, 1968, at 6:01 p.m., as King stood on the second-floor balcony outside his room at the Lorraine Motel, he was struck by a single rifle shot.⁴³⁴⁴ He was pronounced dead at St. Joseph's Hospital at 7:05 p.m. at the age of 39.⁴⁵

News of King's assassination sparked civil unrest and riots in more than 100 American cities. Days later, Congress passed the Civil Rights Act of 1968, which included the Fair Housing Act banning discrimination in the sale, rental, and financing of housing. In May and June 1968, King's successor at the SCLC, Ralph Abernathy, carried out the Poor People's Campaign in Washington, establishing a 3,000-person protest encampment known as Resurrection City on the National Mall for six weeks.

Following a two-month international manhunt, James Earl Ray, a 40-year-old fugitive who had escaped from the Missouri State Penitentiary in April 1967, was arrested at London's Heathrow Airport on June 8, 1968.⁴⁶ Extradited to Memphis, Ray pleaded guilty on March 10, 1969, to the first-degree murder of King in order to avoid the death penalty, and was sentenced to 99 years in prison. Three days later, Ray recanted his confession, claiming for the remainder of his life that he had been set up as a scapegoat by a shadowy figure named "Raoul" as part of a broader conspiracy. Ray died in prison from complications of hepatitis C on April 23, 1998.

Questions surrounding the assassination prompted multiple official inquiries. In 1979, the House Select Committee on Assassinations concluded that Ray had fired the fatal shot from a rooming house bathroom window across from the motel, that his story of "Raoul" was not credible, and that no federal, state, or local government agency was involved in the assassination, though it noted a likelihood that Ray may have had assistance from private right-wing conspirators. Conversely, the King family came to believe that Ray was innocent. In 1999, the family brought a wrongful death civil lawsuit in Memphis against retired local businessman Loyd Jowers; a civil jury reached a unanimous verdict finding that Jowers and unnamed co-conspirators, including governmental agencies, were part of a conspiracy to kill King. A subsequent investigation by the U.S. Department of Justice under Attorney General Janet Reno in 2000 disputed the civil verdict and found no credible evidence to overturn the conclusion that Ray was the assassin. In July 2025, a federal judge lifted a sealing order ahead of its 2027 expiration to release previously classified government records related to King's surveillance and assassination.

King is widely recognized as one of the most influential figures in modern American history, and his nonviolent philosophy has inspired human rights movements worldwide. He was posthumously awarded the Presidential Medal of Freedom in 1977 and, jointly with Coretta Scott King, the Congressional Gold Medal in 1994. Following his death in 1968, Coretta Scott King founded the Martin Luther King Jr. Center for Nonviolent Social Change in Atlanta as a living memorial dedicated to advancing his work.

After a 15-year campaign led by civil rights advocates and Coretta Scott King, President Ronald Reagan signed legislation on November 2, 1983, establishing Martin Luther King Jr. Day as a federal holiday observed on the third Monday of January.⁴⁷ In 1996, Congress authorized the creation of a national memorial in Washington, D.C., initiated by King's collegiate fraternity, Alpha Phi Alpha.⁴⁸ Located in West Potomac Park along the Tidal Basin at 1964 Independence Avenue SW—an address commemorating the Civil Rights Act of 1964—the Martin Luther King, Jr. Memorial opened to the public in August 2011 and was formally dedicated on October 16, 2011.⁴⁹ Designed by the ROMA Design Group and sculpted in pink granite by artist Lei Yixin, its centerpiece is a 30-foot relief of King on the "Stone of Hope" emerging from the "Mountain of Despair," a motif drawn from his 1963 "I Have a Dream" speech, making King the first African American and fourth non-president honored with a major memorial on the National Mall.⁵⁰