Juneteenth is observed every year on June 19 and commemorates the liberation of the last slaves in Texas, two years after the Emancipation Proclamation had abolished slavery in the Confederate States.
It was not until Union soldiers arrived in Galveston, Texas, on June 19, 1865, that the state’s residents finally learned that slavery had been abolished. The former slaves immediately began to celebrate with prayer, feasting, song, and dance.
Many observe the date with local celebrations, including parties, parades, picnics and festivals and the Bay Area is no exception. source: Ronnie’s list.