Rare additional map issued by Vandermaelen, showing how his atlas volumes of North America and South America could be joined to form a single map.

The map shows Upper California and Texas as part of Mexico, a massive Oregon Territory and a excellent treatment of the River Systems of the Western US, following Lewis & Clark and Pike’s Expeditions.

Vandermaelen’s work was a cartographic landmark, being the first atlas of the world to be produced on a uniform scale. In fact, the various sheets were constructed in order to allow for the sheets to be joined to form a massive globe. The work was a tremendous success and a number of the map sheets were modified one or more times during the publication of the atlas, which comprised 6 volumes (North America, South America, Africa, Europe, Asia and Oceana.

Vandermaelen’s atlases each included a key sheet, but in later editions, this special map was issued to show how the sheets from different volumes could be joined.