In the 1850 US Census for Rumney, Grafton County, New Hampshire Joseph P. Barnum was enumerated with his mother and sister, as follows:
Dwelling #71; Family #71
Caroline Barnum, 41, F, b. New Hampshire
Caroline E. Barnum, 12, F, b. New Hampshire
Joseph Barnum, 11, M, b. Vermont, Attended school within the year
In the 1870 US Census for Laconia, Belknap County, New Hampshire the family of Joseph P. Barnum was enumerated as follows:
Dwelling #114; Family #138
Barnum, Joseph P.; 31; M; W; House painter; b. Vermont; Male citizen of US of 21 years of age and upwards
Barnum, Sarah A.; 26; F; W; Keeping house; b. New Hampshire
Barnum, Iantha M.; 6; F; W; Attending school; b. New Hampshire; Attended school within the year
Barnum, Lola M.; 4; F; W; b. New Hampshire
In the 1880 US Census for District 9, Laconia, Belknap County, New Hampshire the family of Joseph P. Barnum was enumerated as follows:
Dwelling #149; Family #234
Barnum, Joseph P.; W; M; 41; Divorced; Painter; b. Vermont; Both parents b. Vermont
Barnum, Ianthia M.; W; F; 16; Daughter; Single; At school; Attended school within the year; b. New Hampshire; Father b. Vermont; Mother b. New Hampshire
Barnum, Lola M.; W; F; 14; Daughter; Single; At school; Attended school within the year; b. New Hampshire; Father b. Vermont; Mother b. New Hampshire
Webb, Alfred; W; M; 43; Boarder; Single; Harness maker; b. England; Both parents b. England
In the 1910 US Census for District 12, Sanbornton, Belknap County, New Hampshire the family of Joseph P. Barnum was enumerated as follows:
Dwelling #43; Family #43
Barnum, Joseph P.; Head; M; W; 71; 2nd marriage; Married 28 years; b. Vermont; Both parents b. US; Speaks English; Retired glazier; Out of work full year; Can read and write; Rents farm home; Farm Schedule 39
Barnum, Dollina; Wife; F; W; 65; 1st marriage; Married 28 years; Mother of 0 children; b. Canada; Both parents b. Scotland; Immigrated to US in 1825; Speaks English; No occupation; Can read and write