Tomorrow morning, Joe Kings of Portland, Me., will be up at dawn to get the fire going. Every year on the third Saturday in June, Mr. Kings's barbecued ribs, corn and spicy red beans draw hundreds of Maine residents -- most of them white -- to his celebration of a Texas holiday once celebrated only by blacks: Juneteenth.
With events including a small rap contest in Anchorage and a huge festival of African-American heritage in Baltimore, hundreds of thousands of Americans will celebrate Juneteenth, the day slavery in the United States effectively ended. With the arrival of an Army ship in Galveston on June 19, 1865, Texas was the last state to learn that the South had surrendered two months earlier. More than two years after the Emancipation Proclamation went into effect on Jan. 1, 1863, the 250,000 slaves in Texas were finally freed.
Juneteenth, which is traditionally celebrated on the third Saturday in June, began taking root across the country largely because of enthusiastic black ''Texpats'' like Mr. Kings, a retired Army medical administrator who spent 11 years stationed at Fort Hood, Tex. After buying a car repair business in Portland, he held a Juneteenth picnic the very first year.
''Even the black people here didn't know about Juneteenth,'' Mr. Kings said. ''Now the white ladies come by on the first of June and start asking: 'When's Juneteenth?' ''
With its lighthearted name and tragicomic origins, Juneteenth appeals to many Americans by celebrating the end of slavery without dwelling on its legacy. Juneteenth, its celebrators say, is Martin Luther King's Birthday without the grieving.
''When I think of Martin, I can't help but see the dogs and the sticks and the little girls in the church,'' said Paul Herring, who has organized Juneteenth celebrations in Flint, Mich., for 10 years. ''But when I think of Juneteenth, I see an old codger kicking up his heels and running down the road to tell everyone the happy news.''
Most gatherings are decidedly upbeat, but the sobering reason for the holiday has also been part of Juneteenth's growth. Dr. Ronald Myers, the leader of a movement to make Juneteenth a national holiday, says June 19 should be an annual remembrance of the horrors of slavery.
''We never got our apology, so we need this holiday to remind us that we must not forget,'' said Dr. Myers, who spoke yesterday at a Juneteenth event at the Capitol led by Representative Danny K. Davis, Democrat of Illinois.
On Wednesday, the New York Legislature passed a bill to make Juneteenth an official, if ceremonial, state holiday, joining 13 other states, including New Jersey, Connecticut, Alaska, California and Texas.
Juneteenth celebrations range from backyard picnics to more formal events. In Hartford, the Wadsworth Atheneum art museum will open its 13th Juneteenth celebration with a black-tie gala on Friday night; in Guam, Anderson Air Force Base will celebrate with a dominoes tournament and gospel concert.
Monique Wells, a Houston native, organizes an annual Juneteenth picnic in Paris. ''The first year, no one but me had even heard of Juneteenth,'' Ms. Wells said. ''But everybody likes it. There's nothing sad about Juneteenth.''
The holiday has taken root even in communities with relatively tiny black populations, like Portland and Chandler, Ariz., where a Miss Juneteenth pageant will be held Friday. Arizona's population is less than 4 percent black, but Lavon Woods, a pageant organizer, said: ''There are always lots of white people who come. We don't have too many parties here as good as Juneteenth.''
Alison Hood, who is white, said that as a girl growing up in Austin, Tex., she always envied the black children who went to big barbecue picnics and drank ''red soda water'' -- strawberry soda, a Juneteenth tradition. Now, she says, she goes to the Austin picnic every year.
Blacks welcome the integration of the holiday.
''You'd think the end of slavery would be a holiday for all Americans,'' said Wade Woods, a member of the committee for Juneteenth in San Francisco, often cited as the oldest civic celebration outside the Southwest; Texas' neighboring states also have extensive celebrations. In the 1950's, Mr. Woods said, a transplanted Texan named Wesley Johnson put Juneteenth on the map there by annually donning a ten-gallon hat and riding a white horse down Fillmore Street -- then the main drag of the black neighborhood.
This year, San Francisco's 54th Juneteenth event, which includes a posse of black cowboys, is expected to draw about 50,000 spectators.
Juneteenth has been a state holiday in Texas since 1980, and the political issues it raised then are now on the national stage. Some Texas lawmakers objected to the holiday as a glorification of black ignorance; others claimed there were already occasions enough on the calendar to recognize the African-American experience, including Emancipation Day, celebrated on Jan. 1, the day Lincoln's proclamation went into effect.
And with Martin Luther King's Birthday established as an official forum for discussions of race, some still question the need for ''another'' black holiday, Mr. Herring said.
''But this is our day to be happy,'' he said. ''I'm glad as hell that the U.S. got its freedom on July Fourth, but were my ancestors free that day? I don't think so.''
Photos: Shamaka Thomas is in a Miss Juneteenth pageant in Chandler, Ariz. (Photo by Jeff Topping for The New York Times); Santie Huckaby finishing a banner for San Francisco's celebration. (Photo by Peter DaSilva for The New York Times)(pg. A28)