The maps, scanned at high resolution and full scale, are some of the most beautiful I've seen.
The following files are hosted by the U.S. Army Corps of Engineers.
1. Geological Investigation of the Alluvial Valley of the Lower Mississippi River - Fisk, 1944 Report (197MB)
2. Oversized Plates - Fisk, 1944 Report (686MB)
3. Oversized Plates Rectified - Fisk, 1944 Report (369MB)
You can also preview the maps on Flickr
Lower Mississippi Valley: Engineering Geology Mapping Program