ANDREWS AIR FORCE BASE, Md. -- Andrews Gospel Mass Choir, sings a gospel song in recognition of Andrews Fourth Juneteenth celebration June 13, in front of Chapel 3. Juneteenth, also known as Emancipation Day or Freedom Day, is the oldest known celebration commemorating the ending of slavery in the United States, dating back to June 19, 1865. (U.S. Air Force photo by Bobby Jones)