In Philadelphia, graphic representation of the city's spatial relationships has existed since William Penn directed his Surveyor General, Thomas Holme, to prepare Portraiture of the City of Philadelphia in 1682. Since that moment, thousands of maps of the city, its region and its individual parts, have appeared both in manuscript and published forms. Owing both to their innate natures and their areas of concentration, each collection contains strong and weak points, but together they house all of the major published maps of the city and its region and a majority of the minor ones needed for historical research. In addition, comparatively few manuscript maps have escaped their clutches. Smaller collections throughout the entire metropolitan region, i.e. Temple University's Urban Archives, help fill what gaps exist.
Most people are probably aware of a number of different types of maps through daily usage.
The common street map, transportation maps, topographic and geologic maps, newspaper maps used to illustrate current events or the results of a political election, general maps of the world and different countries, and advertisers' maps deigning to show the location of a particular business often form the limit of the average person's contact with maps. Private publishers and governmental agencies have intended most of their maps to depict current data. These attempts to illustrate current data captures the city at an instant in its history. Each type of map mentioned above seeks to serve a different audience. Owing to this decided bias, one must always remember that these documents are not infallible.