If the Potomac has been much studied, it has nevertheless been subjected to only meager "development" over the centuries of its service to civilized men. Most past attempts to alter it significantly for man's use have either failed or have not led to lasting results, though their changing purposes over the years summarize, to a degree, America's shifting attitudes toward the utility of flowing water. Early projects under George Washington and others to assure the navigability of the main river above the Fall Line, which they saw as an artery for eastward and westward currents of trade, left only some quaint ruined locks and flowing bypass canals around falls and rapids. The later C. & O. Canal, which ran alongside the river and was replenished by its water above occasional low dams, required over two decades of toil and death and heavy expense to complete upriver to Cumberland, Maryland, which it reached in 1850. There had been some public opposition to the project and it was never a great success even after completion, for the railroad era had begun and the Canal suffered periodic heavy damage from Potomac floods, being finally abandoned to picturesque decay after a mighty inundation in 1924. Largely because of a stalemate between public and private power advocates, the early 20th century heyday of small-scale hydroelectric power development of rivers mainly missed the Potomac, though at one time a power company acquired land at Great Falls in anticipation of such development. Other modern water projects in the Basin have been relatively modest or have run afoul of strong opposition. Therefore, today a sprinkling of small channel power dams and water intake structures, some levees and improved creek channels, and a few unimposing reservoirs of various sizes and types high up on small tributaries are the sum total of the development to which the Potomac water resource has been lastingly subjected, if we disregard for the moment its waste disposal function and the maintenance of navigation in its estuary. In general this is undoubtedly a fortunate thing, for the application of modern technology to rivers in the past half-century of our national growth has not always had happy results. "A river," Justice Holmes once wrote, "is more than an amenity, it is a treasure." His feeling is shared by thousands upon thousands upon thousands of people who live along the Potomac and its tributaries or who go there to float down them in bass time, to picnic and swim, to hunt, to dig into the region's history, or just to listen to the purl of green water against the rough stonework of a ruined bridge pier. Deteriorated though a few stretches may presently be, these rivers are still treasures.