Steven Williams, a fifth-grade teacher at Stevens Creek School in the San Francisco Bay area suburb of Cupertino, sued for discrimination on Monday, claiming he had been singled out for censorship by principal Patricia Vidmar because he is a Christian.

"It's a fact of American history that our founders were religious men, and to hide this fact from young fifth-graders in the name of political correctness is outrageous and shameful," said Williams' attorney, Terry Thompson.

"Williams wants to teach his students the true history of our country," he said. "There is nothing in the Establishment Clause (of the U.S. Constitution) that prohibits a teacher from showing students the Declaration of Independence."

Vidmar could not be reached for comment on the lawsuit, which was filed on Monday in U.S. District Court in San Jose and claims violations of Williams rights to free speech under the First Amendment.

Phyllis Vogel, assistant superintendent for Cupertino Unified School District, said the lawsuit had been forwarded to a staff attorney. She declined to comment further.

Williams asserts in the lawsuit that since May he has been required to submit all of his lesson plans and supplemental handouts to Vidmar for approval, and that the principal will not permit him to use any that contain references to God or Christianity.

Among the materials she has rejected, according to Williams, are excerpts from the Declaration of Independence, George Washington's journal, John Adams' diary, Samuel Adams' "The Rights of the Colonists" and William Penn's "The Frame of Government of Pennsylvania."

"He hands out a lot of material and perhaps 5 to 10 percent refers to God and Christianity because that's what the founders wrote," said Thompson, a lawyer for the Alliance Defense Fund, which advocates for religious freedom. "The principal seems to be systematically censoring material that refers to Christianity and it is pure discrimination."

In June, the U.S. Supreme Court refused to hear the case of a California atheist who wanted the words "under God" struck from the Pledge of Allegiance as recited by school children. The appeals court in California had found that the phrase amounted to a violation of church and state separation.