Jonathan Vernet Cilley was born on 17 November 1863 at Brooklyn, New York.^3,4 He was the son of Commander Greenleaf Cilley and Malvina Vernet.² He married Germana Domenella, daughter of Eliseo Domenella and Maria Capitani.¹ He died on 9 October 1947 at Buenos Aires, Argentina, at age 83.¹
     Jonathan Vernet Cilley was also known as Juan Vernet Cilley.¹
     Jonathan Vernet Cilley appeared on the 1880 Federal Census of Orono, Penobscot, Maine, enumerated 1880, age 16, born in New York, in college, father was born in Maine and mother was born in South America.⁵ As of 1880, Jonathan Vernet Cilley was also known as J. Y. Cilly the 'Y' may be a mis-read 'V'.⁵
     Jonathan Vernet Cilley appeared on the 1880 Federal Census of Rockland, Knox, Maine, in the household of General Jonathan Prince Cilley.⁶ He was graduated in 1883 from Maine State College at Orono, Maine with a bachelors degree in Civil Engineering.¹
     A civil engineer and graduated from the Maine State College as BCE in the class of 1883, returning to Buenos Aires in the same year. He immediately entered the employ of the Provincial Government of B.A. as an assistant engineer and was engaged on the contsruction of railways from Buenos Aires to La Plata, La Plata to Magdalena, Nueve de Julio to Trenque Lauquen, and Bragado to Lincoln in the construction of these two last roads he was the superintending engineer. He surveyed the route for railways from Trenque Lauquen to Guamini and Trenque Lauquen to Touay. He was the inspector general of the Provincial Railway, the Sectional Engineer of section three and four Western Railway.¹ He was attending the 54th class reunion in June 1937 at Orono, Maine.¹