Juneteenth is the oldest-known celebration of the ending of slavery. The observance of June 19 as African-American Emancipation Day has spread across the United States. Historians note that the celebration of Juneteenth originates from Galveston, Texas. NPR's Tavis Smiley talks with Pam Tilley, historian for the Lay Organizations in Texas with the African Methodist Episcopal (AME) Church. They are also joined by Texas Rep. Al Edwards.