Washington prime meridian. "Entered according to Act of Congress, in the year 1856, by Charles Desilver in the Clerks Office of the Eastern District of Pennsylvania." 30. in upper right margin. Inset: Western part of michigan [ca. 1:3,000,000] 1 map : col. ; 34 x 27 cm. This map is in the public domain. Please attribute access and use of this digitized map to the Stephen S. Clark Library, University of Michigan Library.