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March on Washington, 1963 - The March on Washington was held in Washington, D.C. on August 28, 1963.

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March on Washington, 1963 - The purpose of the march was to advocate for civil and economic rights for African Americans.

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March on Washington, 1963 - King and other civil rights leaders gathered at the Lincoln Memorial before the rally.

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Meeting John F. Kennedy, 1963 - President John F. Kennedy met with the visiting civil rights leaders at the White House on the same day.

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"I Have a Dream" - King's "I Have a Dream" was a defining moment of the civil rights movement, and remains one of the most evocative public speeches ever made.

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Meeting Robert Kennedy, 1963 - Attorney General Robert F. Kennedy met with King in Washington later that same year.

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Receiving the Nobel Peace Prize, 1964 - In October 1964, King traveled to Oslo, Norway to receive the Nobel Peace Prize.

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Receiving the Nobel Peace Prize, 1964 - He was recognized for combating racial inequality through nonviolent resistance.

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The Civil Rights Act, 1964 - The Civil Rights Act of 1964 was signed into law by President Lyndon B. Johnson at the White House. He is pictured presenting King with the pen used to sign off on the historic document.

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The Civil Rights Act, 1964 - The actual Title VII of the Civil Rights Act of 1964 document and as well as the pen used to sign it is on display in the East Room of the White House.

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With Lyndon B. Johnson, 1965 - The civil rights leader made several visits to Washington to confer with LBJ.

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Alabama March, 1965 - The images documenting the civil rights movement have become some of photojournalism's most powerful and iconic.

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March 1965 anti-march poster - Photographers were on hand to witness an incredibly important chapter in American history.

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Alabama March, 1965 - The pictures captured the struggle by African-Americans for equal rights, and were often taken in hostile environments.

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Mississippi Freedom March, 1966 - This march was particularly fraught with danger. Participants, including King, faced death threats, arrests, and tear gas.

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Birmingham County Jail, 1967 - Incarcerated in Birmingham County Jail, King received several telegrams of support, including this message from boxer Muhammad Ali.

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April 4, 1968 - After stepping out of Room 306 at the Lorraine Motel in Memphis, King was felled by an assassin's bullet.

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Lying in state, 1968 - King's murder shocked the nation, and the world.

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Funeral service,1968 - A day earlier, he'd delivered his "I've Been to the Mountaintop" address, in which he suggested he might not have long to live.

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Anger and unrest, 1968 - The assassination led to a nationwide wave of race riots.

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The assassin - The gunman, James Earl Ray, was convicted in 1969 of King's murder, and sentenced to 99 years in jail. He died in prison in 1998.

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Coretta Scott King, 1968 - After her husband's death, Coretta Scott King established her own distinguished career as an civil rights activist.

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The Lorraine Motel, 1991 - After falling into disrepair and closing, the hotel became the National Civil Rights Museum in 1991. It underwent considerable renovation in 2014.

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National Civil Rights Museum, 2014 - The museum complex encompasses adjacent buildings including the boarding house (pictured) where James Earl Ray is believed to have fired the fatal shot.

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National Civil Rights Museum, 2014 - Exhibits trace the history of the Civil Rights Movement in the United States from the 17th century to the present.

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National Civil Rights Museum, 2014 - It also houses a jail cell replica of where King was imprisoned.

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National Civil Rights Museum, 2014 - Multi-media and interactive exhibits, including photographic contact sheets and numerous short movies, enhance the museum experience.

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National Civil Rights Museum, 2014 - Included is a replica of the bus Rosa Parks took in 1955, when she famously refused to give up her seat to a white passenger.

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Rosa Parks - An activist herself, she passed away in 2005, aged 92.

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Rosa Parks - Congress called her "the first lady of civil rights" and "the mother of the freedom movement."

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Named in honor - Many roads and streets across the country are named for King and Rosa Parks.

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Stamp of approval, 1999 - The 1999 "I Have a Dream" stamp was issued in September of that year, 20 years after the "Black Heritage Series" stamp was issued.

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"Bloody Sunday" anniversary, 2000 - President Bill Clinton, Rev. Jesse Jackson, and Coretta Scott King, attending an event in Selma marking the 35th anniversary of the march called "Bloody Sunday," which led to the Voters Rights Act of 1965.

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Death of Coretta Scott King, 2006 - King's widow passed away in January at age 78, in Rosarito Beach, Mexico.

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Death of Coretta Scott King, 2006 - Rev. Jesse Jackson was clearly upset at her passing.

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Death of Coretta Scott King, 2006 - Among those who attended the funeral was Stevie Wonder, who sang during the ceremony.

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Martin Luther King Jr. Historic District - King and his wife are entombed at the King Center, Martin Luther King Jr. Historic District, Atlanta.

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The first African-American president, 2009 - Barack Obama became the first African-American President of the United States. His election epitomized everything the Civil Rights Movement stood for.

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The first African-American president, 2009 - The crowd's elation was evident.

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The first African-American president, 2009 - The inauguration ceremony was among the most-observed events ever by a global audience.

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Martin Luther King Jr. Memorial, 2011 - The imposing sculpture was inaugurated in August and is sited in West Potomac Park next to the National Mall in Washington, D.C.

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Ebenezer Baptist Church, 2011 - King's son, Martin Luther King III, addresses a crowd at the historic Ebenezer Baptist Church.

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Rosa Parks statue unveiled, 2013 - President Barack Obama unveiled the full-length statue in the Capitol's National Statuary Hall.

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Commemorative Freedom Walk, 2013 - Jesse Jackson and other civil rights leaders commemorate the famous march.

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Historical drama - Actor David Oyelowo played King in the biopic 'Selma' (2014). It garnered several Oscar and Golden Globe nominations.

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Selma revisited, 2015 - President Barack Obama speaks in front of the Edmund Pettus Bridge in Selma, the scene of a violent confrontation between marchers and police and state troopers.

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National Historic Trail - The route the marchers took is now a designated National Historic Trail.

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Selma, Alabama. Today - A bust of Martin Luther King Jr. is pictured in Selma, Alabama.

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MLK Day -

Marking his birthday, MLK Day is observed on the third Monday of January each year, and is an annual federal holiday.

Now that you're here, have a look back at 1968.

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