In the 1850 US Census for New York Ward 10, New York, New York the family of Joshua Barnum was enumerated with the family of Eliza Duff, as follows:
Dwelling #990, Family #2312
Joshua Barnum, 31, M, Merchant, b. New York
Catherine A. Barnum, 31, F, b. New York
Stephen C. Barnum 5, M, b. New York, Attended school within the year
From The New York Times, 27 Mar 1884: Death of a Clothing Merchant. Joshua Barnum, of the firm of J. Barnum & Son, clothiers died yesterday at his home near, Brewsters. He was born at South-East, Putnam County, on Sept. 3, 1818, and coming to this city his sixteenth year, he was employed as a clerk in the clothing house of Brooks Brothers. His first venture in business for himself was with his father-in-law, the late Henry O. Dusenberry, in the provision trade in Greenwich street, but on the latter's death, he returned to the clothing trade. Mr. Barnum was associated with several fire insurance companies and, was a Director in the Rutgers Company at the time of his death. He was Inspector of Clothing for the Indian Department of the Government, and was a member of the Central Presbyterian Church of South-east.
Gravestone inscription: Lord, I believe. Help thou mine unbelief.
The Milltown Family Cemetery, in Putnam County, is a large cemetery in current use and is easily found on the north side of the Milltown Road.