For those struggling in Sanford on Sunday to accept the acquittal of George Zimmerman over the killing of Trayvon Martin, there were combative sermons and prayers for understanding, but little immediate solace.

"I couldn't go to sleep last night and I didn't want to awaken this morning, to the devastating reality that hatred, prejudice and injustice pollutes the air of America," said an emotional Pastor Valerie Houston to the strains of Gospel tunes.

"At the expense of the life of an innocent, unarmed African American teenager. America, our country, which professes that we are one nation under God, with liberty and justice for all."

Large crowds of stone-faced worshipers gathered in Sanford, 250 miles (400 kilometers) north of Miami, the morning after the night before, when a jury found neighborhood watch volunteer Zimmerman not guilty of murder.

The long and racially-charged trial transfixed much of the United States.

Zimmerman, 29, had been accused of pursuing Martin, 17, through a gated community in Sanford, and shooting him during an altercation in February last year.

"Dr (Martin Luther) King (Jr) stated, the daily life of the Negro is still in the basement of the Great Society," Houston said. "And today I state, the daily life of my people is still enslaved to a white supremacist society."

Still, she insisted: "We are not at the bottom unless we continue to see ourselves there, the innocent shed blood of Jesus, Dr. Martin Luther King Jr, Medgar Evers, Emmett Till and Trayvon Martin should propel us to soar to higher levels in all areas of society."

Geraldine Burke, 88, in a red hat and black pumps, said: "Today I felt it was necessary to come to church to be united as community. It's a sad day for us and for the country, another sad day of our sad history in our beloved country."

Allen Chapel in Sanford's Goldsboro neighborhood welcomed many locals to worship not far from the scene of Martin's death. Others drove from miles away specifically to be here, in this mostly-white small city of 54.000, such was their frustration at the verdict.

"This is the worst lesson that we could have from our justice system, but we must continue to trust in our judicial system. Violence is not the answer," insisted churchgoer Dominique Washington.

"This trial began by asking if Trayvon Martin was criminal or victim. Now it is clear to us that Zimmerman was a criminal because he followed Trayvon because he wanted to do it. Zimmerman was a criminal because he used a gun and used violence."

Florida's "Stand Your Ground" law, however, allows armed people who feel threatened to shoot in self-defense, and such was the argument that Zimmerman's attorneys made successfully to a six-woman jury.