Juneteenth (a portmanteau of "June" and "nineteenth") celebrates the actual liberation of the last enslaved persons in America, which occurred on June 19th, 1865, when the Union General Gordon Granger arrived in Galveston, Texas, and issued General Order No. 3, which read:

The people of Texas are informed that, in accordance with a proclamation from the Executive of the United States, "all slaves are tree." This involves an absolute equality of personal rights and rights of property between former masters and slaves, and the connection heretofore existing between them becomes that between employer and hired labor.

The fact that there were still people living in slavery at this time often comes as a surprise to people, given that the Emancipation Proclamation had been signed on January, 1, 1863. It's important to remember, however, that the Emancipation Proclamation only declared that slaves were free (it also excluded the Union slave states of Maryland, Delaware, Missouri, and Kentucky). A great deal of legislation in the form of the 13th, 14th, and 15th Amendments (and, of course, the defeat of the Confederacy), were required to truly secure and ratify the liberation of black Americans.

Keen-eyed readers will probably also note that June 19th was a good two months after the surrender of General Robert E. Lee at Appomattox, which helps illustrate the significance of this holiday. Slave owners did not happily grant their slaves manumission, they very often had to be coerced or forced by either the Union army or by the threat of and actual resistance of the slaves themselves (many historians have argued, convincingly, that Lincoln was merely granting legitimacy to a growing movement of slave agitation and rebellion, and that black people freed themselves). The project of emancipation was piecemeal and hard-fought across the United States, especially in the South.

Juneteenth (sometimes called Freedom Day, Jubilee Day, or Liberation Day), immediately became a day of celebration in the South, especially in Texas and the neighboring states, where one of the first actions of newly emancipated slaves was to try to reunite with lost family members. The first Juneteenth celebration was held in 1866 and marked by sharing food, singing, prayer, dressing in fine clothes, and spread quickly to nearby southern states, but also California and other areas of the west as black Texans migrated elsewhere (documented well in Isabel Wilkerson's The Warmth of Other Suns). As a nod to its origins with Black Texans, Juneteenth celebrations, then and now, often include rodeos and barbecues, and even pilgrimages to Galveston.

In the late 19th and early 20th century, as black Americans began to fall under the growing suppression of Jim Crow, a more insidious form of historical compromise suppressed the importance of Juneteenth and other holidays, like Decoration Day, which initially celebrated former slaves in Charleston honoring the Union dead, in favor of conciliatory remembrances like the Memorial Day that we still celebrate (though not specifically about Juneteenth, David Blight's Race and Reunion is a critical text for understanding the place of the Civil War in American Memory). In many ways, Juneteenth celebrations were a distinct counter to the whitewashing of the past and the growing push to reconcile with the memory of the Confederacy:

Juneteenth celebrants still did their own remembering, in Hayes Turner’s words, to project “identification with American ideals” in “a potent life-giving event … a joyful retort to messages of overt racism … a public counter-demonstration to displays of Confederate glorification and a counter-memory to the valorization of the Lost Cause.”1

Black Americans never stopped celebrating Juneteenth, especially in Texas, but it wasn't until the success of the Civil Rights movement that it moved back into the national consciousness and spread widely across the country. After MLK's assassination in 1968, his planned Poor People's March ended on June 19th, and many civil rights leaders took the idea of the celebration home with them. Texas was the first state to make it an official state holiday in 1980, and most now recognize it in some fashion or another.

Obviously the conversation about Juneteenth and the negotiation of historical memory goes on, but that’s about as far as we can go without running into the twenty-year rule.