JENA, La. -- In a scene reminiscent of the civil rights rallies of the 1960s, thousands of people came to this town yesterday from across the country in support of six black high school students accused in the beating of a white classmate.

Throughout the sunny, hot day, protesters poured from buses, vans, cars and even limousines, most in black T-shirts that read "Free the Jena Six" or other rallying slogans, including the famous quotation from the Rev. Dr. Martin Luther King: "Injustice anywhere is a threat to justice everywhere."

The crowd, estimated by police at between 15,000 and 20,000, jammed Jena's downtown streets and city park. Arriving from numerous states and at least one foreign country, they listened to a parade of speakers on a platform in front of the LaSalle Parish Courthouse, including the Rev. Jesse Jackson and the Rev. Al Sharpton. The crowd, which organizers claimed was as large as 50,000, was a cross-section of toddlers, students and senior citizens, blacks and whites, and members of a variety of religions.

Like the boycotts of two generations past, yesterday's protest forced the closing of schools, public offices and businesses in the mostly white community of about 3,000.

"This is the new Selma. This is the new Birmingham," said Charles Steele Jr., president of the Southern Christian Leadership Conference, the organization headed by Dr. King during the height of the civil rights movement.

"We're going to make the Selma movement look like a Sunday school picnic," Mr. Steele said amid cheers.

The rally was planned for yesterday because one of the so-called Jena Six, Mychal Bell, was scheduled to be sentenced. The 17-year-old was convicted of conspiracy to commit second-degree battery in the December beating of Justin Barker, a white Jena High School classmate.

Last week, however, a state appeals court threw out the conviction, stating that Mr. Bell should not have been tried as an adult. He, along with four other black teens, initially were charged with attempted murder in the incident. That charge was reduced to battery for all but one, who has yet to be arraigned. The sixth teen was charged as a juvenile.

The beating was the result of an incident that occurred in August 2006, when a black student asked at a school assembly whether blacks could sit under a shade tree where white students commonly congregated.

He was told yes, but the next day, two nooses appeared on the tree. Three white students were suspended in the incident but not criminally charged. School officials called it an "adolescent prank."

Subsequent fights among students culminated in Mr. Barker's beating.

Mr. Bell is the only one of the six still in jail, having been unable to raise the $90,000 bail.

The national spotlight spurred a number of people, including celebrities, to contribute money to defray the black teens' legal fees. David Bowie announced Wednesday he would donate $10,000 to the fund, while musical acts Lloyd, Jagged Edge, Tank, Bobby Brown, Twista and others have scheduled a performance dubbed the Jena Six Empowerment Concert in Birmingham, Ala., on Sept. 29.

Protesters vowed yesterday not to spend one cent in Jena. But that doesn't mean that money didn't change hands.

Don Clark, a real estate agent from Monroe, La., stood atop a recreational vehicle with a microphone encouraging people to donate to Mr. Bell's legal defense fund.

Jewel Crawford, of Atlanta, collected the money in a cardboard box.

"I'm a social justice activist," she said. "And this is injustice. I've been in the struggle for years since I was a teenager.

"They're attacking our children and we can't have that."

By 2 p.m. yesterday, Ms. Crawford had collected $20,000.

Ahmad Ahamad, who came from his home in Cancun, Mexico, said the rally will have a significant impact if people follow up.

"This is just the first step as far as I'm concerned," he said.