The American Congress of Obstetricians and Gynecologists, formerly the American College of Obstetricians and Gynecologists, is a professional organization with over 50,000 members.

William Frey, a senior demographer at the Brookings Institution, analyzed the census data showing that for the first time fewer than half of American households are headed by married couples.

The Marriage & Religion Research Institute archives data about marriage from a number of sources. It also posts links to scholars around the country.

The National Conference of State Legislatures’ website includes a summary page on marriage.

Judy Waxman is the vice president and director of health and reproductive rights at the National Women’s Law Center, which works to protect women’s reproductive rights. Contact Maria Patrick.

Nancy Northup is the president and CEO of the Center for Reproductive Rights, a global human rights organization that uses constitutional and international law to secure women’s reproductive freedom. Contact senior press officer Kate Bernyk.

William Saunders is senior vice president for legal affairs and senior counsel at Americans United for Life (AUL). He directs AUL’s international project and writes and speaks on a wide-range of life-related and human rights topics.

Susan Low Bloch is a law professor at Georgetown University. She is an expert in constitutional law, communications law and courts and judges and she teaches a seminar on the Supreme Court.

Randy E. Barnett is the Carmack Waterhouse Professor of Legal Theory at Georgetown University. He is an expert in constitutional law and contracts.