July 13, 1787: Congress passed the Northwest Ordinance, creating the Northwest Territory.
This map is one of the oldest non-facsimile maps of North America that we have in the Map Collection. Iowa is located roughly where the “Octotatas” (most likely the Otoe) are depicted.
Particularly interesting is the information found in the bottom left corner of the map, which explains the cartographer’s sources rather thoroughly.
Map: A new & accurate map of Louisiana : with part of Florida and Canada and the adjacent countries drawn from surveys, assisted by the most approved English & French charts the whole being regulated by astron.l observations / by Eman. Bowen. [London] : Eman. Bowen, [1747?]