Nieuport 11 & 16, part two. The 'Bébé' in service with the Lafayette Escadrille

 

Although officially the United States did not employ nor the Nieuport 11 or 16, the American volunteers serving with the French Aéronautique Militaire (French Aerial Arm) piloted the Nieuport 11, in the famous N124 Escadrille, AKA Lafayette Escadrille.
This unit was formed officially on 16th April 1916 and consisted mainly of American volunteer pilots and was initially known simply as Escadrille de Chasse Nieuport 124 (Escadrille Américaine) (Nieuport Fighter Squadron 124 - American Squadron). It was formed at Luxeuil-les-Bains in France, close to the Swiss border, where the pilots were trained. 
The unit proved soon to be very valuable by both Frenchs and Americans, because before the First World War airplanes were not considered to be useful in combat. 

The Lafayette Squadron (as it was more commonly known) was equipped with the Nieuport 11 since January 1916 at their training site. Apparently, the initial equipment consisted on a mixture of Nieuport 11 and 17s, with some 16s too. It was in those 'Bébés' when the unit saw its baptism of fire on 13th May 1916 at the Battle of Verdun and, five days later, on 18th May 1916 Kiffin Rockwell scored the unit's first aerial kill. Weeks later, on 23rd June, the escadrille suffered its first casualty when Victor Chapman was shot down over Douaumont, in the Meuse department. It's hard to know when the Nieuport 11 were replaced by either Nieuport 17s or SPAD S.VIIs, but it is know that the 'Bébés' didn't see active service beyond summer 1916.

Sources:
1st https://en.wikipedia.org/wiki/Lafayette_Escadrille
2nd http://albindenis.free.fr/Site_escadrille/escadrille124Lafayette.htm (translated)

3rd Flying Machines Press  - French Aircraft of the First World War

4th Osprey - Aviation Elite 17 - Lafayette Escadrille American Volunteer Airmen In WWI