Sixty years ago, the excessively high rates of maternal and infant mortality in this country posed a major social problem. A series of prospective surveys designed and carried out by the U.S. Children's Bureau established that many of these deaths were related to the poor condition of the mother and could be prevented. Overcoming opposition from a conservative federal government, the American Medical Association, and a coalition of ultraconservative groups, social workers lead a campaign which resulted in passage of the Sheppard-Towner Act in 1921. The work accomplished under this act contributed substantially to the reduction of infant mortality in the United States, demonstrated the effectiveness of such preventive health services, and established the principle of shared federal-state responsibility in matters of health and social welfare.