United States. Department of the Interior, The Nation's River: A report on the Potomac
“ As civilized rivers go, the Potomac is rather lucky. It is polluted, but many parts of it are not nearly as dirty as people are sometimes led into believing by a look at the summertime estuary at Washington. The fabled and scenic German Rhine, for instance, is much more degraded in its main flowing reaches than is the Potomac, and so are a majority of the other rivers in the northeastern United States and many elsewhere in the country. Industrialization on the Potomac and its tributaries has been spotty so far, and there are no really big clusters of population in the upper parts of the Basin. ”
