Corps of Engineers involvement in navigation projects dates to the early days of the United States, when rivers and waterways were the primary paths of commerce in the new country. Without its great rivers, the vast, thickly-forested, regions west of the Appalachians would have remained impenetrable to all but the most resourceful early pioneers. Consequently, western politicians such as Henry Clay lobbied for Federal assistance to improve rivers. At the same time the War of 1812 showed the importance of a reliable inland navigation system to national defense.
There was, however, a question as to whether transportation was, under the Constitution, a legitimate Federal activity. This question was resolved when the Supreme Court ruled that the Commerce Clause of the Constitution granted the Federal Government the authority, not only to regulate navigation and commerce, but also to make necessary navigation improvements.
The system of harbors and waterways maintained by the Corps of Engineers remains one of the most important parts of the Nation's transportation system. The Corps maintains the Nation's waterways as a safe, reliable, and economically efficient navigation system. The 12,000 miles of inland waterways maintained by the Corps carry one sixth of the nation's inter-city cargo. The importance of the Corps mission in maintaining depths at more than 500 harbors, mean-while, is underscored by an estimated one job in five in the in the United States being dependent, to some extent on the commerce handled by these ports.