Chesapeake and Ohio Canal National Historic Park is a unit of the National Park System, which consists of more than 400 parks representing important examples of our country's natural and cultural inheritance. This park preserves one of the Nation's most intact historic canals. It also fortuitously protects part of the Potomac River Valley as a natural, historical, and recreational resource of inestimable value. This handbook is published in support of the National Park Service's management policies and interpretive programs at the park. Part 1 places the park in its historical setting—the 19th-century canal era—and tells how citizen initiative eventually saved it from highway building. Part 2 explains how the canal was built, how it worked, who made it work, and what it contributed to developing agriculture, mining, and industry in the Potomac River basin. Part 3 presents concise travel guide information, detailed canal maps, and other reference materials to help you make the most of a visit to the canal.