The Marriage Law Project (MLP) is a public interest legal aid organization founded in 1996. It aims "to reaffirm marriage as the union of one man and one woman." Its offices are located in the Columbus School of Law at The Catholic University of America in Washington, D.C. Its founder, David Orgon Coolidge, was Senior Fellow at the Columbus School of Law Ethics and Public Policy Center and a Research Fellow in the Columbus School of Law Interdisciplinary Program in Law and Religion. William C. Duncan is assistant director of the Marriage Law Project.