, 30.2 Printed at the bottom of the map: Extra session of Congress map. Price 25 cents. General map of the eastern United States showing finished railroads, railroads in progress,...
From these histor- ical evidence, plague seems to have difficulties spreading to the blocking part of these rivers/canals. It might be rather preliminary to conclude that the blockage of those rivers drove plague away from inland waterways. There is a lack of available literature to validate ...