"It's kind of a double whammy to be African-American and Muslim," said Jackson, who studies the Navy at the National Academy of Science in Washington. "You're going to be judged."

Jackson's struggle may have gotten harder when the FBI on Wednesday raided a Detroit-area warehouse used by a Muslim group. The FBI said the group's leader preached hate against the government, trafficked in stolen goods and belonged to a radical group that wants to establish a Muslim state in America. The imam of the group's mosque, a black American named Luqman Ameen Abdullah, was killed in a shoot-out with agents.

Yet the Muslim faith continues to convert many average African-Americans, who say they are attracted by Islam's emphasis on equality, discipline and family.

"The unique history African-Americans have faced, we're primed for accepting Islam," said Jackson, 31, who grew up in a secular home and converted to Islam when he was about 18.

"When someone comes to you with a message that everyone is equal, that the only difference is the deeds that they do, of course people who have been oppressed will embrace that message," Jackson said. "It's a message of fairness."

It was a message of black pride in the face of dehumanizing prejudice that launched Islam in America in the 1930s.

Created by a mysterious man named Wallace Fard, the "Lost-Found Nation of Islam" strayed far from the teachings of the prophet Muhammad, but its mixture of self-reliance, black supremacy and white demonization resonated with many blacks. Some 30 years later, Malcolm X began the African-American movement toward traditional Islam when he left the Nation of Islam, went on a pilgrimage to Saudi Arabia and proclaimed that not all whites are evil.

In 1975, the Nation split into two factions: a larger group that embraced orthodox Sunni practices, and another, led by Louis Farrakhan, that maintained the Nation's separatist ideology.

Today, it is difficult to determine the number of Muslims in America. A 2007 Pew survey estimated 2.35 million, of whom 35 percent were African-American. Lawrence Mamiya, a Vassar College professor of religion and Africana studies and an expert on American Islam, said Muslim organizations count about six million members, a third of them black.

Most African-American Muslims are orthodox Sunnis who worship in about 300 mosques across the country, Mamiya said. The second-largest group follows Farrakhan's Nation of Islam, which has about 100 mosques in America, abroad and in U.S. prisons, Mamiya said.

He said the third-largest group is the Ummah, founded by Jamil Abdullah Al-Amin, the black activist formerly known as H. Rap Brown. The group has about 40 to 50 mosques. The organization targeted in the raid near Detroit was part of the Ummah, the FBI said.

"The vast majority of African-American Muslims are using the religion to strengthen their spirituality," said Mamiya, who has interviewed many black Muslim leaders and congregants. He said the number of black Muslims is growing, but not as fast as before the 9/11 terrorist attacks.

Few white Americans convert to Islam "because the tendency is to view Islam as foreign," he said. "For African-Americans, it's part of their African heritage. There's a long tradition [in Africa] . . . . It moves them away from the Christianity they saw as a slave religion, as the religion that legitimized their slavery."

Margari Hill was a California teenager seeking an antidote for nihilism and widespread disrespect of black women when she found Islam in 1993. A few years ago she began covering her hair with a hijab, or head scarf.

"I wanted to be thinking about humility and modesty," said Hill, 34, a teacher in Philadelphia. "I decided it would help me be a better Muslim and a better person."

Hill's husband, Marc Manley, said that many blacks who have struggled with crime, drugs or alcohol are drawn to Islam's regimented lifestyle, which includes prayers five times a day.

"Especially in the urban context, it provides a vehicle for African-Americans to deal with those ills," he said. "It provides a buffer or a barrier."

At the Quba Institute in Philadelphia, a black Sunni mosque, the worshippers are a mix of blue-collar workers, young college graduates, professors, law enforcement officers, and "regular people who are just trying to worship God and live a decent life," said the imam, Anwar Muhaimin.

Muhaimin was born into a Muslim family after his parents embraced Islam in the 1950s. He grew up in Saudi Arabia, "but was very clear from a young age that I was and am an American citizen."

"America is my country, I love the United States," he said. "I don't agree with everything our politicians do in our name, but that doesn't mean I'm not a citizen of this country."