modelfflyingboat

Was this the first ever hydroplane?

No, this was August, 1916, so long after its invention.
en.wikipedia.org/wiki/Seaplane#Early_pioneers

see notes under

LOC: Should be "Kendrick's Plane"

Art Siegel: Thanks. We'll be sure to pull together all of the Hendrick/Kendrick records for updating.

The ship in the background is the frigate Granite State, originally USS New Hampshire (1864). en.wikipedia.org/wiki/USS_New_Hampshire_%281864%29 See article in The New York Times, November 2, 1915 "NAMES FLYING BOAT FOR NAVAL MILITIA"

Thanks B-59. We will add the name of this ship to the description when we update.

To the right of the frame is the fantail of the New York Naval Militia's Patrol Yacht USS Wasp (1893). See: en.wikipedia.org/wiki/USS_Wasp_(1893) www.navsource.org/archives/12/130095d.htm www.navsource.org/archives/12/130095.htm

Navy pilot born 1886; name is also spelled McCullough (interchangeably, it seems, on this bio): earlyaviators.com/emccullo.htm

He was engaged in the attempt to cross the Atlantic, together with H.C. Richardson and others.
Richardson:

see comments there

Thanks pennylrichardsca and B-59. We will include his name variants and more information about him when we update.

See comment under After a lot of digging, "McCulloch" is the correct spelling.