James Dwight Dana’s research while affiliated with Philadelphia ZOO and other places

... The richly fossiliferous Neogene sediments have been recognized for the paleoclimatic signals they contain since the time of Lyell's visit in 1845 [26]. The term "Yorktown," referring to beds on both the York and James Rivers in Virginia, enjoys frequent use in the early literature including but not limited to Dana's "Yorktown", "Yorktown Period", and "Yorktown Epoch" [27][28][29]. Dall and Harris [30] referenced "the Yorktown", but the first reference to the "Yorktown Formation" was made by Clark and Miller in 1906 [31]. In 1912, Clark and Miller state "The Yorktown Formation has been so named because of the excellent exposure of the strata of this age in the prominent cliffs at Yorktown [32]." ...

Reference:

The Yorktown Formation: Improved Stratigraphy, Chronology, and Paleoclimate Interpretations from the U.S. Mid-Atlantic Coastal Plain