Through the Louisiana Purchase in 1803, the United States expanded its size by over 800,000 square miles. But neither President Thomas Jefferson nor Congress knew exactly what they had bought until 1806, when Meriwether Lewis and William Clark returned from their famous expedition. One of the most significant contributions of the Expedition was a better perception of the geography of the Northwest. Lewis and Clark prepared approximately 140 maps and filled in the main outlines of the previously blank map of the northwestern United States. Robert I. Field has done much the same for the vast territory of U.S. health care regulation.On the front cover of Fields new book, Health Care Regulation in America: Complexity, Confrontation, and Compromise, is a picture of a giant three-dimensional labyrinth. Rarely is cover art so perfectly appropriate.