In the 1850 US Census for Monkton, Addison County, Vermont the family of Philemon Barnum was enumerated as follows:
Dwelling #33; Family #33
Philemon Barnum, 39, M, Farmer, Real property $5,000, b. Vermont
Rebecca Barnum, 34, F, b. Vermont
Orton T. Barnum, 12, M, b. Vermont, Attended school within the year
Jerome Barnum, 8, M, b. Vermont, Attended school within the year
Sarah Roscoe, 19, F, b. Vermont
Philemon was a bloom iron manufacturer, and a son of Job V. Barnum, who was also born in Addison County, Vermont. Job Barnum was a son of Ebenezer Barnum, who was an early settler there and was a native of Connecticut.