JENA, La. -- Drawn by a case tinged with one of the most hated symbols of Old South racism -- a hangman's noose tied in an oak tree -- tens of thousands of protesters rallied Thursday against what they see as a double standard of prosecution for blacks and whites.

The plight of the so-called Jena Six became a flashpoint for one the biggest civil-rights demonstrations in years.

Protest regulars like the Revs. Jesse Jackson and Al Sharpton joined scores of college students bused in from across the nation who said they wanted to make a stand for racial equality just as their parents did in the 1950s and '60s.

"It's not just about Jena, but about inequalities and disparities around the country," said Stephanie Brown, 26, national youth director for the NAACP, who estimated about 2,000 college students were among the throngs of mostly black protesters who overwhelmed this tiny central Louisiana town.

But the teens' case galvanized demonstrators as few legal cases have in recent years.

Jackson, who led a throng of people three blocks long to the courthouse with an American flag resting on his shoulder, likened the demonstration to the marches on Selma and the Montgomery bus boycott in Alabama. But even he was not entirely sure why Jena became the focal point.

"You can never quite tell," he said. "Rosa Parks was not the first to sit in the front of the bus. But the sparks hit a dry field."

Martin Luther King III, son of the slain civil rights leader, said punishment of some sort may be in order for the six defendants, but "the justice system isn't applied the same to all crimes and all people."

People began massing for the demonstrations before dawn Thursday, jamming the two-lane highway leading into town and parking wherever they could. State police estimated the crowd at 15,000 to 20,000. Organizers said they believe it drew as many as 50,000.