Went to Paris in 1780 at the age of 16 and worked for Franklin until both returned to the United States in 1785.
In later life, Mumford was a representative in the United States Congress (1805-11) and a successful banker in New York.
Nephew of Silas Deane, who was married to Mumford's mother's younger sister. Married in 1793 to Anna Van Zandt; two sons. Married in 1810 to Letitia Van Toren; seven children survived infancy.