British Burgess-Dunne AH-7 Tailless Swept-Wing ‘Hydroaeroplane’ flying just over the water off Pensacola, Florida. USS Columbia (C-12) anchored in the background - March 1916

In May 1914, Naval Constructor Holden C. Richardson had recommended that the Navy buy two of these planes to study the new development in aeronautical design.
With manufacturing rights licensed to the Burgess Company of Marblehead, Massachusetts, the British Burgess-Dunne tailless aircraft was built in two versions: AH-7 and AH-10. The U.S. Navy's first experiments in aerial gunnery were conducted in these aircraft.
AH-7 first flew on October 10, 1914, and was delivered to Pensacola shortly thereafter. At one point, it was modified with bomb racks under the left wing, and there is some indication that for a time it wore a lavender and green camoflage paint scheme (which must have been quite a sight! Sadly, vintage black-and-white photos often don't convey such chromic brilliance). It was gone from the Navy's records by January, 1916.
AH-10 entered the record books on April 23, 1915 when Lt. Patrick L. N. Bellinger piloted her to a new US altitude record, 10,000 feet, over Pensacola during a 1 hour, 19 minute flight. Bellinger, who was Naval Aviator No. 4, was one of the first Navy pilots to see combat, in Vera Cruz, Mexico, and was nominated for a Medal of Honor (though ultimately not awarded). He later flew Curtiss NC-1, one of the three Nancy Boats to attempt to cross the Atlantic (only NC-4 made it; Bellinger and NC-1 had to put down near the Azores due to heavy fog, and the plane was damaged beyond repair by the heavy seas). Bellinger ultimately retired in 1947 as Vice Admiral after serving as Commander, Air Force, Atlantic Fleet.
The US Army Signal Corps had shown interest in the design as early as 1913, and when Burgess started building them, they placed an order, receiving hydroaeroplane BD-3 (marketed as the "Burgess-Dunne Military Aeroplane"), powered by a nine-cylinder Salmson radial engine, as Army serial number 36. It was delivered December 30, 1914 to North Island, San Diego. Unlike the early models with their flat decks on which the pilot and passenger sat, the BD-3 had a rather boxy nacelle, complete with 1/8 inch thick nickel steel armor plate, making this the heaviest version yet built. It was also equipped with a machine gun at the forward crew station (the pilot sat in the aft) and so although this wasn't the Army's first airplane (they'd bought a number of Wright flyers), since it was armed it was hailed in the contemporary media as the Army's first "warplane". In the spring of 1915, it was modified as a land plane and assigned to the Army's Coast Artillery for use as fire control support. It had been dropped from inventory by October 18, 1916.

#1 - AH-7 flying just over the water off Pensacola, Florida. USS Columbia (C-12) anchored in the background.

 

#2 - AH-7 on a takeoff run during Navy sea trials. Off the Pensacola, FL coast.

 
#3 - Burgess-Dunne ‘Military Aeroplane’ advertisement.