The colorful story of his life would be unbelievable if made into a movie. Pioneer, merchant, explorer, surveyor, map maker, patriot, rebel, and finally Lord! Accurate maps are always desirable, but in the late 1600s crucial for establishing boundaries of the new colonies. Herman's map was based on that of Capt. John Smith's map of Virginia of 1612. That map, created in the time of Shakespeare, and just 100 years after the invention of movable type printing was oriented the way a mariner would enter the Chesapeake --> from left to right.
King Charles I subsequently gave Maryland to the first Lord Baltimore in 1631. (See the pdf of orignal charter -- 1 mb). The charter specifies the 40th parallel as the northern limits of the grant. The Augustine Herman map 40 years later had considerably greater detail in the area of Maryland than the John Smith map. After the Maryland charter there was a beheading of Charles I, civil war, protectorate of Cromwell, another civil war and now in 1681 a charter to William Penn. Both the Herrman map and one sold by John Speed just 3 years later include New Castle, and its position as related to the 40th parallel. This was important, as detailed in an article on mapping Pennsylvania, since the border between Pennsylvania and Maryland at the 40th parallel was based on the charter of King Charles I in 1631 as amended by King Charles II to give to Penn, which specified the boundary as a circle 12 miles from the New Castle Courthouse, and then west along the 40th parallel. As noted in the Mapping Pennsylvania, there was a considerable variation in the location assigned to New Castle. The map even included soundings of the Delaware River off the town of New Castle - 4-6 (fathoms? - 24-36 feet).
Herrman's son Ephraim lived in New Castle, at least originally in the lot next to the current Read House, and subsequently near the site of Fort Casimir at Chestnut and 2nd streets. Augustine disowned Ephraim because of his involvement with the pietist Labadie sect.