Pat founded the Citizens Committee for Humane Abortion Laws promoting safe and legal abortions in San Francisco around 1962. Later renamed the Society for Humane Abortion (SHA), the committee worked to educate medical and legal personal while running a free post-abortion clinic. Additionally, the SHA ran an underground network helping women access abortions. Obtaining abortions was extremely hard to do as it was rare doctors granted exceptions for "therapeutic abortions." Maginnis and other activists would encourage and teach women seeking abortions how to fake these conditions (psychosis, excess vomiting, etc). She handed out leaflets on how a woman could terminate a pregnancy and taught ways to induce abortion at home. Pat was arrested several times as she often went against anti-abortion laws. 