Author of the first American botanical publication, Arbustum Americanum: The American Grove. John Bartram’s printed catalogs of American plants in the 1730s were early publications, primarily intended to advertise and sell seeds. Humphry Marshall’s Arbustum Americanum (1785), however, is recognized as the first American botanical publication in the sense of a formal scientific book, with detailed descriptions and observations of trees and shrubs.

 The Second Botanic Garden in Colonial Pennsylvania
Created by Humphry Marshall in 1773
His Cousin, John Bartram, had the First Botanic Garden:

  Twin brothers, Samuel and Joshua Peirce, were Quaker farmers who created Peirce’s Park, which evolved to become Longwood Gardens. These twin brothers received title to the Peirce estate in 1800. Their mother was a niece of botanist Humphrey Marshall. The Peirce boys spent many hours here in the Marshall arboretum.
By 1850 the Peirce family had developed Peirce’s Woods into one the finest arboretums in the county. In 1906 Pierre du Pont purchased the property to preserve the trees. So today the countless visitors to Longwood Gardens from around the world can thank Humphry Marshall for helping to inspire Longwood.