While the origin of the name is unknown, the details of Henry were published in June 6, 1956 Sports Illustrated – The Biggest Elephant Ever Killed By Man. Big game hunter Josef Fénykövi hunted the elephant on his ranch in Angola and later donated it to the Natural History museum. It took sixteen months for Smithsonian taxidermists to prepare Henry for display (Wash. Examiner). In 1999, it was restored (Scripps Howard Foundation Wire) and given a more realistic exhibit.
By the way, the museum seems to keep a hungry 4½ year old occupied for about an hour which is fine since we’re local. The cafeteria isn’t cheap ($22 for an adult and child) but above average. We mostly went through the dinosaur exhibit and that was fairly enjoyable for the 4½ year old mentioned above. More trips are sure to follow. Archives (yellow/green) and Smithsonian (blue/orange) are the closest Metro stops.