This map of Philadelphia was published in London in 1777 by William Faden, successor to Thomas Jefferys as royal geographer to King George III. It is based on a 1752 map prepared by Nicholas Scull (circa 1687–1762) and George Heap (flourished 1715–60), updated with new details. An important addition to the 1777 map is the shading to indicate the expansion of the city from the waterfront along the Delaware River. One of the largest and most prosperous cities in mid-18th century British North America, Philadelphia was laid out in a rectangular pattern across a two-mile (3.2-kilometer) grid between the Delaware and Schuylkill Rivers. The map has a watermark and shows roads and the names of landholders in rural areas. It includes a table of distances and a view of the State House, the building that was completed in 1753 as the colonial legislature of the Province of Pennsylvania, and which is now known as Independence Hall. Scull, who was born near Philadelphia, was a member of what is believed to be the first American family to engage in cartography as a business. He was surveyor general of the colony of Pennsylvania in 1748–61.