(CNN) -- Maj. Gen. Gordon Granger of the Union Army announced to the assembled crowd at Ashton Villa in Galveston, Texas, "In accordance with a proclamation from the Executive of the United States, all slaves are free." It was June 19, 1865. Never mind that President Abraham Lincoln's Emancipation Proclamation had been written and read more than two years earlier. Juneteenth, named for the June 19 declaration, started as a celebration of emancipation day in Texas and eventually spread to other states. With celebrations dating back to 1866, Juneteenth now commemorates the end of slavery in the United States. "America cannot understand its own history unless the African-American experience is embraced as a central factor in shaping who we are and what we have become as Americans," writes Lonnie G. Bunch, founding director of the Smithsonian National Museum of African-American History and Culture in Washington.
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African-Americans, both enslaved and free, built the city of Charleston
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Nicodemus, Kansas, is oldest surviving African-American town west of the Mississippi
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St. Helena Island, in South Carolina, was a safe haven for freed people as early as 1862
Set to open in 2015, the museum will be the only national museum devoted exclusively to the documentation of @placeholder-American life, art and culture.