The date was chosen because it is the date in 1973 when the U.S. Supreme Court, in the infamous case of Roe v. Wade, held that a woman's right to an abortion fell within the right to privacy protected by the Fourteenth Amendment. States may no longer ban abortions before the fetus is determined to be "viable."

Many churches celebrate Sanctity of Human Life Sunday on the third Sunday of January—the Sunday before the anniversary of the Roe decision. On this Sunday, sermons were preached on the national sin of abortion, literature was passed out regarding the evils of abortion, gruesome pictures were shown of dead fetuses and botched abortions, the horrors of partial-birth abortion were explained, the further liberalization of abortion laws in states like New York was denounced, and Planned Parenthood was singled out for condemnation (but probably not the "pro-life" Republicans who continue to fund the organization).