Reading Howell's map a cartographic landmark in the mapping of Pennsylvania and one of the most influential maps of Pennsylvania to be published. '
First issued in 1792, Howell's map is the first large format map of Pennsylvania published in America following the Revolution. Wheat & Brun describe the map as the best map of Pennsylvania published in the 18th Century. The map is the earliest map of Pennsylvania to show its exact boundaries, including the western limits. For the first time on a printed map Howell records the information gathered from many original surveys made after the Revolutionary War and during a time of rapid westward expansion. Shows towns, roads, boundaries donation lands, and extensive topographical detail. Originally issued in four sheets, the map was published over a period of several months, with many additions and corrections to the map of historical interest, and which are also useful in identifying the various states of the four plates.
A reduced 2 sheet edition was subsequently issued 1792 and a very rare enlarged state in 1811 (the present example), which includes a large decorative cartouche not present in earlier editions. The map remained the most accurate map of Pennsylvania until the publication of Melish's map of Pennsylvania in 1820. This third edition, published by Kimber & Conrad & Johnson & Warner in 1811 and was subsequently issued in 1816 and 1817.