The news of freedom came late to more than 250,000 enslaved black people in Texas.

On June 19, 1865 — more than two years after President Abraham Lincoln had issued the Emancipation Proclamation, freeing the slaves in Confederate states — Maj. General Gordon Granger stood at the Headquarters District of Texas in Galveston and read “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.”

Black people who heard the news erupted in celebration.

“They spent that night singing and shouting,” remembered Pierce Harper, a formerly enslaved woman, in 1937, according to “Slave Narratives” interviews collected by the Works Progress Administration. “They weren’t slaves no more.”

Ever since, African Americans across the country have marked that day of liberation with a holiday known as Juneteenth. President Trump announced Wednesday that he planned to resume holding his political rallies — in Tulsa on June 19, the celebratory day of Juneteeth. Tulsa is the site of one of the worst episodes of racial violence in U.S. history: the 1921 race massacre.

The announcement that Trump would hold a political rally on Juneteenth in a city where as many as 300 black people were killed by mobs of white people shocked some historians.

“It’s almost blasphemous to the people of Tulsa and insulting to the notion of freedom for our people, which is what Juneteenth symbolizes,” said CeLillianne Green, a historian, poet, lawyer and author of the book “A Bridge: The Poetic Primer on African and African American Experiences.”

“I’m speechless. That day is the day those people in Texas found out they were free. The juxtaposition of the massacre of black people and Juneteenth, the delayed notice you are free, is outrageous. Juneteenth symbolized our freedom.”

In an interview with Fox News, Trump said the date for the Tulsa rally wasn’t intentional, but “you can really think about that very positively because a rally to me is a celebration.” But by late Friday night, he reversed himself, announcing on Twitter that he would delay the rally by a day to avoid holding it on Juneteenth.

Juneteenth is one of the oldest official celebrations commemorating the end of slavery in the United States. Celebrations of Juneteenth — which combines the word June with Nineteenth — began in 1866, a year after Granger landed on Galveston Island with more than 2,000 Union troops. Texas slave owners had refused to acknowledge the end of the Civil War and Lincoln’s Emancipation Proclamation.

“There are many possible explanations for the delay” in the word reaching enslaved people in Texas, according to the Amistad Center for Art and Culture in Hartford, Conn. “A messenger may have been killed on his way to Texas with the news of freedom or maybe the news was deliberately withheld by the enslavers to maintain the free labor force on the plantations. Another possibility is that federal troops waited for the slave owners to have one last cotton harvest before going to Texas to enforce the Emancipation Proclamation. For whatever the reasons, slavery in Texas remained beyond the legal deadline.”

More than 100 years later, Juneteenth celebrations have spread across the country and around the world, including to Canada, Nigeria and Japan. The history of how and when freedom came to slaves in this country is complicated, historians say. Many people believe that Lincoln’s Emancipation Proclamation freed all enslaved black people.

“Lincoln’s edict had little impact on the people of Texas, since there were few Union troops around at the time to enforce it,” according to the Library of Congress. “But with the surrender of Gen. Robert E. Lee in April 1865 and the arrival of Gen. Gordon Granger’s regiment in Galveston, troops were finally strong enough to enforce the executive order.”

Lincoln had issued a warning in September 1862, telling rebellious Confederate states to rejoin the Union by Jan. 1, 1863, or “freedom would be granted to slaves within those states.”

When the states refused, Lincoln made good on that threat. On Jan. 1, 1863 — as the country entered the third year of the Civil War, Lincoln issued the Emancipation Proclamation, which declares:

That on the 1st day of January, A.D. 1863, all persons held as

slaves within any State or designated part of a State the people

whereof shall then be in rebellion against the United States shall

be then, thenceforward, and forever free."

But the Emancipation Proclamation was narrow in its focus. “It applied only to states that had seceded from the Union,” according to the National Archives, “leaving slavery untouched in the loyal border states. It also expressly exempted parts of the Confederacy that had already come under Northern control. Most important, the freedom it promised depended upon Union military victory.”

Black people waited impatiently for the moment of that freedom.

That anticipation was captured in a painting that hung outside the Oval Office in the White House during the presidency of Barack Obama. On Juneteenth in 2016, Obama, the country’s first black president, described the painting, which depicted “the night of December 31, 1862. In it, African American men, women and children crowd around a single pocket watch, waiting for the clock to strike midnight and the Emancipation Proclamation to take effect. As the slaves huddle anxiously in the dimly lit room, we can sense how even two more minutes seems like an eternity to wait for one’s freedom. But the slaves of Galveston, Texas, had to wait more than two years after Lincoln’s decree and two months after Appomattox to receive word that they were free at last.”

In 1941, Laura Smalley, a former slave in Texas, told a WPA worker about the day she heard of her freedom.

“I remember the next morning we all got up and all of them went to the house to see old master. I thought old master was dead, I didn’t know he was gone to war,” according to a recording of her interview stored at the Library of Congress. “But he came back. All [the slaves] gathered around to see old master. Old master didn’t tell us we was free. He worked them six months and turned them loose on the 19th of June. That is why we celebrate that day, colored folks celebrate that day, celebrate that day, celebrate that day.”

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