Why is June 19th known as Juneteenth? The answer is rooted in history. “Juneteenth is an African-American holiday that celebrates the emancipation of slaves in Texas in 1865,” Scholar Lori Brooks told InsideEdition.com. Dr. Brooks explained that when Union General Gordon Granger arrived in Texas, it was June 18, “and the next day he announced the emancipation of African-American slaves.” Dr. Brooks added that the holiday gained new interest in the 1960s, as part of the Poor People’s Campaign.