PHILADELPHIA — Saying America is so mired in “moral depravity” that only a mass appeal to the Almighty can save it, Christian evangelical leaders from across the country are planning a giant prayer rally for Sept. 29 in Philadelphia.

The “America for Jesus” daylong gathering on Independence Mall is expected to draw at least 30,000 people who “want to turn the nation around,” said Bishop Anne Giminez, chairwoman of the event and pastor of Rock Pentecostal Church in Virginia Beach, Va.

“We see the symptoms of decline all around us,” she said, citing murder and abortion rates and the decline of marriage. In the past, she also has pointed to the ailing economy and catastrophic weather as warning signs.

Giminez and other leaders were in Cherry Hill, N.J., this week for an organizational meeting with about 80 area pastors.

Philadelphia was chosen for the assembly, and a youth rally the night before, because the American struggle for independence, born in this city, was an outgrowth of the “Spiritual Awakening” movement of the early 18th century, Giminez said.

“We wanted those great symbols, such as Independence Hall and the Liberty Bell, around us.”

Noting that the gathering will precede the presidential election by 40 days, organizers said “America for Jesus” will be free of partisan politics.

“We don’t feel a man can save America,” Giminez said, referring to the presidential contenders. “God is our only hope.”

The history of “America for Jesus” suggests a Republican leaning, however.

On April 29, 1980, Giminez’s late husband, Bishop John Giminez, convened the landmark “Washington for Jesus” prayer rally in the nation’s capital attended by an estimated 500,000.

Organizers included televangelist Pat Robertson, the Rev. Jerry Falwell and Campus Crusade for Christ founder Bill Bright, who later told Ronald Reagan, “Mr. President, you were elected April 29, 1980, not in November.”

Historians agree that the rally was a watershed in the emergence of conservative Christians as an electoral force.

Speaking at John Giminez’s funeral in 2008, historian Vinson Synan of Regent University, founded by Robertson, described the 1980 rally as “calling the nation to God, and evangelicals and charismatics back to the ballot box.”

Giminez and the others also convened prayer rallies in Washington in 1988, 1996 and 2004.