Communities have long commemorated emancipation in the United States with different events (observed on different dates) such as Watch Night, Jubilee Day, and Emancipation Day (see more In K. Jones (Ed.). (2019). African-American Holidays, Festivals, and Celebrations: The History, Customs, and Symbols).
"On “Freedom’s Eve,” or the eve of January 1, 1863, the first Watch Night services took place...enslaved and free African Americans gathered in churches and private homes all across the country awaiting news that the Emancipation Proclamation had taken effect...Only through the Thirteenth Amendment [passed and ratified in 1865] did emancipation end slavery throughout the United States. But not everyone in Confederate territory would immediately be free. Even though the Emancipation Proclamation was made effective in 1863, it could not be implemented in places still under Confederate control...Freedom [in Texas] finally came on June 19, 1865, when some 2,000 Union troops arrived in Galveston Bay, Texas. The army announced that the more than 250,000 enslaved black people in the state were free by executive decree. This day came to be known as "Juneteenth," by the newly freed people in Texas."
As historian Giuliana Perrone says,
"The order effectively announced to enslavers that the United States military would enforce the Emancipation Proclamation in their jurisdiction. Granger’s troops did not just bring news of Confederate surrender, they brought soldiers – including regiments from the U.S. Colored Troops – to enforce it...[Enslaved people] worked to free themselves. They fled across battle lines, abandoned plantations for 'contraband' camps, and enlisted in the Union army. They put their bodies on the line in a collective protest of their subjugation, and forced universal freedom onto the national agenda. In many ways, Juneteenth represented their combined efforts."
As Juneteenth has been celebrated since 1866; most states (including NC) "have passed legislation recognizing it as a holiday or observance" (Congressional Research Service). On June 17, 2021, it became a Federal Holiday.