Juneteenth marks the anniversary of the abolition of slavery in the United States in 1865—the Emancipation Proclamation was signed into law in 1863, and some former Confederate states ignored Abe Lincoln’s executive order for more than two years. In commemoration of the pivotal day in Black American history, this Juneteenth shindig will celebrate the last half-century of hip-hop with a premiere of the fresh pop-up exhibit My Mic Sounds Nice: Hip-Hop Feminism in History, an unveiling of MoPOP’s Online Hip-Hop Collection Vault, panels with hip-hop greats (including MC Sha-Rock and Jarobi from A Tribe Called Quest!), and a freestyle rap battle. While you're there, don't miss the chance to scope out Contact High, the museum's ongoing exhibition of hip-hop photography.