The origins of the holiday is rooted in Galveston, Texas. Texas has recognised Juneteenth as an official holiday since 1980. Other states which see Juneteenth as an official holiday include; Arkansas, California, Conneticut, Massachusetts and New York.
Juneteenth appears in literature too. "Juneteenth", a novel by Ralph Ellison, is about the tradition. This isn't the only novel about this commemoration though. Carolyn Meyer wrote a novel called, "Jubilee Journey". The novel is about a girl, born and raised in Texas who is proud of her African American heritage.
Here is a Youtube clip relating to this holiday:
On this day, many people celebrate it with singing of songs. Two of the most popular songs favoured to sign by celebrants are; "Lift Every Voice and Sing" (informally known as the "The Negro National Hymn," "The Negro National Anthem," "The Black National Anthem," or "The African-American National Anthem") or Swing Low Sweet Chariot.
