This is a Significant Operational milestone.
This was the first practical rotorcraft to fly in the USA.
The aircraft was a Cierva C.8W autogiro flown by British pilot Capt. Herbert (Arthur) Rawson at Pitcairn Field, PA (Pitcairn Field became Willow Grove Naval Air Station). The aircraft was brought from Spain and re-assembled by the Pitcairn Autogiro Company, a company formed by Harold Pitcairn to build and develop autogiros in the USA.
Pitcairn Field is an AHS International Vertical Flight Heritage Site.
Source: "Vertical Flight Historic Aerospace Sites |Pitcairn Field", VFS web page, Last accessed Feb 04 2019