As a historian of the geographical exploration of the American continent by Europeans, Humboldt recognised the value of the early modern maps of America as historical sources. His investigations into the history of cartography, as documented in the manuscripts and sketches of <ref xmlns="http://www.tei-c.org/ns/1.0" target="http://kalliope-verbund.info/DE-611-BF-42738">Volume 9</ref> of the Krakow papers, are another focus of the thematic section.