United States Lines’ SS American Banker left London, England, on March 10, 1939, with 20 foreign passengers on board, according to a manifest provided to US immigration authorities.
Among them was Heinrich Gustav Adolf Detlev Heckscher, who would later be known as Henry Hecksher, the CIA officer at the center of this project.
The 28 year old is described on the manifest as a law student.
He received a visa to the US while in London, on February 1, 1939.
New York, New York Passenger and Crew Lists, 1909, 1925-1957, FamilySearch, s.v. “List or manifest of Alien Passengers for the United States”, https://familysearch.org/ark:/61903/3:1:33SQ-G5ND-5LJ?cc=1923888&wc=MFK7-TWL%3A1030086701, October 2, 2015, citing NARA microfilm publication T715, National Archives and Records Administration.