The Obama administration guidelines, which take effect in August, require insurers to cover all Food and Drug Administration-approved contraceptive methods and sterilization procedures.

U.S. Roman Catholic clergy and others have objected, saying that requiring employers to provide those services through their health plans is a violation of religious freedom, despite promised exemptions and accommodations for religious institutions.

Marie Tasy, executive director of New Jersey Right to Life, organized the Statehouse rally as part of a Nationwide Rally for Religious Freedom to be held in more than 150 cities across the country.

"We understand that this most cherished of rights is under attack, and that is why the Obama mandate must go," Tasy told the crowd.

Tasy said the rallies have nothing to do with contraception, and are instead about protecting First Amendment rights.

"There is no 'war on contraception' in our country," she said. "Contraception is already widely, cheaply available. What's really under attack today is religious freedom."

Many of those who attended the rally gathered at the St. Mary of Assumption Cathedral in Trenton for Mass prior to the event. Bishop David O'Connell encouraged fighting for religious freedom in his message to churchgoers.

O'Connell said the government was created to protect religious freedoms, but now is destroying them through the contraception coverage mandate. O'Connell said even though the nation has faced similar threats in the past, believers can't become complacent on the health care mandate issue.

"Make no mistake about it," O'Connell said. "The stakes are high and the potential consequences are real and dire."

Copyright 2012 The Associated Press. All rights reserved.