The dairy industry underwent dramatic restructuring in the last 50 or so years. The 1997 U.S. Department of Agriculture report by Manchester and Blayney, The Structure of Dairy Markets: Past, Present, Future, described selected dairy product markets, firms in the markets, and changes in the markets and firms for the 1975-99 period. This report provides a similar examination of milk production. Structural changes in milk production are a result of long-term evolutionary processes such as adoption of technological innovations, changes in the production system, and specialization. The key features of milk production examined in this report are the quantity of milk produced and the location, number, size, and business organization of dairy farms.