The Class of 1918 Marsh is a tiny remnant of a large wetland that formerly
covered all of the area now occupied by playing fields, parking lots, and the Nielsen Tennis Stadium. Fifteen thousand years ago when the glaciers receded from this part of Wisconsin, the marsh was connected to Lake Mendota; later a sand bar built up that isolated it from the lake.
The university acquired the land in 1910 and began to experiment with draining the marsh to grow crops, a difficult prospect given that the area is lower than the lake. Tiles were laid and a series of pumps installed. The experiment was considered successful, but by 1965 the tiles came loose and the area reverted to wetland. At this point, the campus was expanding and the university administration planned to use the area for playing fields and parking lots. In the interim they used it as a landfill.