Some rivers that I have lived along and loved, as viewed through the US Library of Congress American Memory. The Library of Congress American Memory presents the user with a search feature and results with a gallery view. The older home page is easier on the eyes, but it will probably disappear. I display screenshot samples so that you may be inspired to find maps relevant to your life.
Most of the maps are available in JPEG 2000 format, and some in MRSID format, neither of which are easy to view in a typical browser. The formats are great, though, because the scans of the maps are huge, yet the files are reasonably sized. The resolution and size of the maps enables excellent zooming. None of the image portions shown here are viewed at or near 100%. I especially appreciate seeing the watersheds as they existed before large portions of them were inundated by dams.
It is also interesting to note which towns were more important to the cartographers, and to observe changes in place names between now and when the maps were made. Here is another great map resource: National Atlas. Highlight these two layers, Water: Dams, and Water: Streams and Waterbodies. The maps of Nouvelle France and the Lewis and Clark Expedition are from the Wikimedia Commons, referred to in the articles "La Salle Expeditions" and Lewis and Clark Expedition".
Indiana - focusing on the forks of the White River and Salt Creek, and some of the Wabash and Ohio Rivers.
Western North Carolina - focusing on the Nantahala, French Broad, Nolichucky, Chattooga, and Green Rivers:
Florida - focusing on the Wekiva, Saint John's, and Econlockhatchee Rivers:
Idaho - focusing on the forks of the Salmon, Clearwater, and Payette Rivers:
New York - focusing on the Niagara River: