Americans will celebrate Juneteenth, which commemorates the end of slavery in the United States, on Friday with parades and parties. Juneteenth became the newest US federal holiday in 2021, but it has held significance for many Black Americans for a long time. On June 19, 1865, Union Army Maj. Gen. Gordon Granger issued General Order No. 3 in Galveston, Texas, proclaiming that enslaved African Americans in that area were free.