Ira Lourie's Johnson Map Project

Dr. Ira Lourie's Johnson U.S. Map Project has studied over 85 atlases from 9 libraries, 4 private collections, and several pre-auction exhibitions. Numerous loose atlas maps have also been studied including a large collection at the Library of Congress. In this study, we have discovered 67 different maps utilized in Johnson atlases. Most all of these maps have had a number of states/variations ranging from 1 to 19, with an average of 9. In the project, we are referring the changes as states/variations because in strict historical map study some of the variations noted might not qualify as "true" map states. However, for the purpose of dating loose maps and tracking the history of the Johnson atlases, these variations are important keys. In all there are 631 different states/variations of the 67 maps.