ENTERTAINMENT : Celebrating Freedom : Museum is reviving a forgotten holiday that marks the end of slavery. The event will explore black cowboys’ role in the Wild West.

Much of Los Angeles joins in to celebrate ethnic holidays such as Cinco de Mayo, Chinese New Year’s and St. Patrick’s Day, but now a local museum is reviving a long-forgotten American holiday commemorating the end of slavery.

Juneteenth is a genuine Southwest holiday started by African-Americans to recall the Emancipation.

The holiday dates back to 1865 and is held in the middle of June, marking the week when word that the slaves were free spread through Texas that year, more than two years after Abraham Lincoln declared that the slaves were free.

“Plantation owners had crops in the fields and didn’t want to tell their slaves that they were free right away, so they got their fields taken care of first,” says Cynthia Harnisch, director of education programs at the Gene Autry Western Heritage Museum, which is sponsoring an authentic re-creation of a Juneteenth family celebration June 19.

“This is a true Southwestern holiday, and we’re trying to reintroduce people to it,” says Harnisch, who recalls it being called a “Black Fourth of July” when she lived in Tucson. This time, it’s geared for everyone.

“Everyone becomes Mexican on the 5th of May; everyone wears green on St. Patrick’s Day. L. A. is multicultural, and we want this to be another holiday that everyone can take part in,” says Don Harvey, a volunteer who helped encourage the museum to highlight the holiday. “I overheard a child in the museum say that there was no such thing as black cowboys. That’s just not true, and this is one way we can explain their history.”

“One in four cowboys was black; people just don’t know that,” says Harvey, a consultant for airport concessions and a Western history hobbyist who collects such things as different versions of the Emancipation Proclamation--which will be on display on Juneteenth.

Harvey takes his 9-year-old son, Aaron, horseback riding in the San Fernando Valley and has entrenched some of the African-American Western history in the boy by telling him stories he has heard from his parents--all in the Juneteenth tradition.

“My family came from Texas, where it’s a state holiday, and we celebrated it every year in Griffith Park with a big picnic, and I used to think everyone there was celebrating the same thing.”

The celebration usually included hymn singing, dramatic readings of the Emancipation Proclamation and playing family games, Western museum researchers Dolores Dyer and Mary Bagley say.

“For some areas of east Texas, this is the biggest day of the year,” Bagley says. “But some families don’t want to commemorate that period of black history anymore.”

The museum’s celebration will include a barbecue, dominoes, checkers as well as ballads by cowboy Herb Jeffries, a visit by celebrities such as Glynn Turmann from “A Different World” and sports greats including old-timers from the original Negro Baseball League.

A historic military re-enactment will take place on the lawn of the museum, along with three-legged races, horse demonstrations and volleyball.

Special exhibits of black history will also be on display with the help of the California Afro-American Museum.

“This is a holiday for everyone to celebrate, to learn and have fun,” says Lori Givens, who is associated with both museums. She invited retired Gen. Celes King, once the highest-ranking African-American military man in California, now a bail bondsman, to come to the event to talk to children.

WHERE AND WHEN

* What: Juneteenth Family Celebration at the Gene Autry Western Heritage Museum, 4700 Western Heritage Way, Griffith Park.

* Hours: 10 a.m. to 4 p.m. June 19 and 20.

* Price: Free; admission to the museum is $6 general, $4.50 senior citizens and students, and $2.50 for children 2 to 12.

* Call: (213) 667-2000.

* What: The California Afro-American Museum, 600 State Drive, Exposition Park.

* Hours: 10 a.m. to 5 p.m. Tuesday through Sunday.

* Price: Free.

* Call: (213) 744-7432.