Today is Juneteenth in the United States – a holiday that is over 150 years old, but is still unknown to many people. It marks the end of official slavery in the country and celebrates the promise of freedom.

The word "Juneteenth" combines the month "June" with the number 19. It recalls June 19, 1865, the day troops from the Union side of the American Civil War arrived in the city of Galveston, Texas.

At that time, Texas was part of the Confederate States of America, the group of Southern states fighting the Union for the right to keep slaves. The 250,000 enslaved people in Texas did not know that the president at the time -- Abraham Lincoln -- had declared them legally free.

FILE - Deborah Smith and her husband, Kuma, watch festivities at a Juneteenth celebration in Los Angeles, June 19, 2010.

In fact, Lincoln had declared them legally free more than two years before – on January 1, 1863.

But Texas was far to the west of the country and removed from much of the fighting. Few Union soldiers were there to communicate or enforce Lincoln's order. Confederate slave holders likely did not care about it or did not agree with it. And they did not want to lose a free labor force.

So, no one told the enslaved people -- until June 19, when a Union general and a few thousand soldiers landed to take control of the area. The general quickly read an announcement. He informed the people that the Union had won the Civil War and "all slaves are free."

Many formerly enslaved people immediately began to celebrate. As soon as they could, some left Texas and joined family members in other states. Some remained and built new lives.

They remembered June 19 in a special way in the years that followed. In time, their children and grandchildren celebrated it as a holiday, too.

What happens on Juneteenth?

Historically, Juneteenth has often involved barbecues, music, prayers and fancy clothes. Betty Anderson, who is a descendant of enslaved people, spoke to The Federalist magazine about her own Juneteenth traditions. She said the day includes stories about people who continued to fight for equal rights because "freedom from slavery did not bring freedom for the African-American."

Historian Henry Louis Gates, Jr. made a similar point on the website The Root. He said one of the important things about Juneteenth is that it is a positive, powerful celebration, even in the face of discrimination.

For example, in the late 1800s and early 1900s, Texas officials refused to permit black people to gather at public spaces. So, black families and friends celebrated Juneteenth near rivers and lakes, Gates said. In time, they bought their own parks where they could celebrate.

A national holiday?

If Juneteenth has been part of American life for hundreds of years, why do many people not know about it?

The Juneteenth website explains that, through the 1800s, the day was well known to many African-Americans. But in the early 1900s, more and more children began leaving their families and going to school. There, the official history books did not tell about Juneteenth – or about the lives of formerly enslaved people in general.

In addition, as the country faced difficult economic times, employers did not permit workers to leave on June 19. Many considered July 4, when Americans mark their declaration of independence from Britain, as a more patriotic celebration.

And so, Juneteenth celebrations decreased.

However, during the country's Civil Rights movement of the 1950s and 1960s, some African-Americans and activists embraced Juneteenth again. The day connected them to black American history, as well as to anyone who was not truly free.

In the late 20th century, Texas declared the day an official state holiday. Other states and cities are also increasingly supporting Juneteenth celebrations. Some activists are calling for it to become a federal holiday.

The Juneteenth website notes that the day honors African-American freedom and achievement. At the same time, it urges continued progress and respect for all cultures.

That website calls it a national day of pride. And a writer for the National Museum of African-American History and Culture in Washington, D.C., calls it "our country's second independence day."

I'm Kelly Jean Kelly.

Kelly Jean Kelly wrote this story for Learning English. Ashley Thompson was the editor.

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