During the US Civil War, a number of proclamations, and general orders freeing enslaved Afrikans were issued. Some Afrikans were emancipated as early as 1861 when Union forces captured outlying areas of the Confederacy such as the Sea Islands of South Carolina, the Tidewater area of Virginia (Hampton and Norfolk) or New Orleans. Other enslaved folks emancipated by escaping during the excitement and disruption of war. Lincoln's Emancipation Proclamation liberated all blacks residing in territory captured from the Confederates after January 1, 1863. Though this act did not end slavery, it was a signal to many Afrikans that if they ran away, the Union forces would protect them. However, for the majority of Afrikan Americans, freedom came only in 1865 when Confederate commander Robert E. Lee surrendered his army to Federal forces at Appomattox Court House in Virginia effectively ending the war. News of Lee's surrender spread quickly through the former slave states east of the Mississippi River but state west of the Mississippi received the news later. Hence, though the war and slavery had potentially ended, many of the enslaved west of the Mississippi remained enslaved. Texas was such a place--it had remained isolated from both Union and Confederate forces during the war. In fact it had become a place of refuge for slaveholders seeking to insure that their "property" would not hear of freedom. So in Texas, the pro-slavery forces manage to keep the new of Afrikan freedom from their enslaved population until June 19, 1865, when Federal troops landed at Galveston, Texas and issued General Order No. 3. Word of emancipation gradually spread over the state.
General Order No. 3
The people of Texas are informed that, in accordance with a proclamation from the Executive of the United States, all slaves are free. 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 Freedmen are advised to remain at their present homes and work for wages. They are informed that they will not be allowed to collect at military posts; and they will not be supported in idleness either there or elsewhere.
By the 1900s these celebrations and festivities had grown to include baseball games, horse races, railroad excursions, and formal balls. By that time Juneteenth had officially become Texas Emancipation Day and was sponsored by black churches and civic organizations. Indeed, Juneteenth had become so respectable that white politicians including various Texas governors addressed the largest gatherings in Houston and Dallas. In Texas in particular, for Afrikan Americans Juneteenth was "the holiday." The Fourth of July paled in comparison.
As the Afrikan population of Texas spread to other western states, they carried the celebration with them and before long Juneteenth was celebrated in Los Angeles, Oakland, Portland, Seattle, and San Diego. The celebration began to spread to communities east of Texas such as Washington, D.C., and Birmingham, Alabama as well.
Economic and cultural forces caused a decline in Juneteenth celebrations beginning in the early 20th century, particularly the Depression.* But by time of the Black Power movement and in many ways because of it, many Afrikan Americans began to revive the celebration. Throughout the 1980s and 1990s Juneteenth has continued to enjoy a growing interest from communities and organizations throughout the country. And you folks in the eight states that don't celebrate it, "What's up?" By the way those states are: Arizona, Hawaii, Maryland, Montana, New Hampshire, North Dakota, South Dakota, and Utah.
*As many Afrikan Americans began to integrate into or identify more with the larger white society, they began to shun Juneteenth and tend to identify and celebrate the national holiday, the Fourth of July. They forgot all about what Frederick Douglass taught them. Click link http://www.historyisaweapon.com/defcon1/douglassjuly4.html, if you need reminding (and have time to read it).