Apprentice/Draftsman, Thomas Ustick Walter, Architect, Philadelphia, PA, c. 1836-1841; Principal, Napoleon Le Brun, Architect, Philadelphia, PA, c. 1842-1865; Principal, Napoleon Le Brun, Architect, New York, NY, c. 1865-1880; Partner, Napoleon Le Brun and Son, Architects, New York, NY, c. 1880-1888; Partner, Napoleon Le Brun and Sons, Architects, New York, NY, c. 1888-1924.

Napoleon Le Brun was born in Philadelphia, PA, in 1821. He lived and worked in the city until c. 1865, when he moved to New York, NY, to establish his architectural office. He remained in New York for the remainder of his career.

His parents were Charles and Adelaide (Madelaine) Le Brun, French Catholics, who came to the US during the reign of Napoleon Bonaparte. Charles served as an Ambassador to the US for the regime. Following Napoleon's final fall from power, the erudite Charles Le Brun worked as a teacher, French translator, and author, and settled in Philadelphia, PA.

Sons, Pierre L.(1846-1924) and Michel Moracin (1857-1913) worked as architects with their father.