Root Nodule Bacteria and Leguminous Plants by Edwin Broun Fred, Ira Lawrence Baldwin, and Elizabeth McCoy first appeared seventy years ago as part of a series, University of Wisconsin Studies (no. 52, Science no. 5), published by the University of Wisconsin in 1932. This work summarized published research in biological nitrogen fixation from approximately 1576 through 1930. A pioneering effort that brought together years of source material from English, German, French, Italian, Dutch, and the Scandinavian languages, Root Nodule Bacteria and Leguminous Plants was a thorough and critical examination that not only synthesized research findings in light of then-current knowledge, but also suggested areas where new research was needed.