From Steve Currall's fascinating piece at Hidden City Philadelphia:
In a way, the modern shape of Philadelphia may be found in the earliest map of southeastern Pennsylvania, that of Surveyor General Thomas Holme and his deputy Robert Longshore. Personally commissioned by William Penn just before he left his nascent colony in 1684, the map stands as a truly remarkable achievement. Holme’s biographer, Irma Corcoran, has rightly called it the “greatest of early American maps,” and a “masterpiece.” Lacking the benefit of modern technology, and forced to deal with the intransigence and fraudulence of his deputy surveyors, Holme was able to depict, with relative accuracy, some 1,800 square miles of Penn’s wilderness. Finishing his draft in 1687, he sent his work to England, for printing and distribution later that year. Those Londoners who first gazed upon the large map (seven sheets of paper, 33.5” by 55.5”) could trace the delineations of most large-to-medium sized tracts then settled within what historian Walter Klinefelter has deemed the most ambitious “disposal of real estate on a scale never before undertaken…the most enterprising ever put into operation for peopling a wilderness.”
The Holme map
During one book discussion, Mark Stein explained the derivation of the semicircular border between New Castle and Chester counties, musing that the “arc inscribes in the shape of Pennsylvania its Quaker past.” Designed to provide a buffer between older Swedish and Dutch colonists and the idealistic Quakers then arriving from across the sea, the 12-mile radius from New Castle Towne, tells of the Society of Friends’ steadfast faith in the geometric order of the universe. Philadelphia’s shape likewise displays this perpetual stamp of Quakerism, as Penn stressed to Holme that his province should be settled in an logical, contiguous fashion “to the end that the Province might not lie like a Wilderness as some others yet do by vast vacant tracts of Land, but be regularly improved for the benefit of Society.”
The serrated nature of much of Philadelphia’s boundaries, arduously traced by late seventeenth century surveyor wheels, then symbolizes the dualistic legacy of Penn’s “Holy Experiment:” a place for both divine order and profitable land speculation.
