This is a scarce Melish issue published to accompany William Maclure's report, Observations on the geology of the United States. This seldom seen map is the one of the first geological maps of the United States. Brightly colored to indicate the location of Primitive Rocks, Transition Rocks, Secondary Rocks, Alluvial Rocks, and Old Red Sand Stone, based on the Wernerian classification system. Also keyed to the legend is a "line to the westward of which has been found the greatest part of the Salt & Gypsum." The map is also filled with information on Indian tribes, forts, roads and early settlements. Illinois Territory is located well away from Lake Michigan and bounded on the north by the large North West Territory. Chicago is correctly located, but is on the border between Indiana and North West Territory. Of particular interest are distance notations along several major roads in miles. A legend locates canals, boundary lines and roads.

William Maclure, who is known as the "father of American geology," published the first widely available geologic map of the United States in 1809. The first edition was based on Lewis' map, whereas this second edition used the Melish map as a base and it was published by Melish. At bottom right, below the border, is "Transactions of the American Philosophical Society Vol. I. New Series." This map is virtually identical to a scarce German edition by Melish titled "Charte der Vereinigten Staaten von Nord America," published in 1813.

References: Rumsey #3954.001.

Condition: B

Folding, as issued. A very nice example with bright color and strong impression printed on thick paper with close margins, as issued. One short marginal fold split, closed on verso, a hint of foxing in blank area left of legend, else very good. A few pencil marks on verso.