In the 1880 US Census for District 45, Portland, Cerro Gordo County, Iowa the family of B. R. Fellows was enumerated as follows:
Household #12; Family #12
Fellows, B. R.; W; M; 32; Married; Farmer; b. Ohio; Father b. Pennsylvania; Mother b. Maine
Fellows; Laura A.; W; F; 29; Wife; Married; Housekeeping; b. Ohio; Father b. Vermont; Mother b. Maine
Fellows, Franklin P.; W; M; 7; Son; Single; Attended school during the census year; b. Iowa; Both parents b. Ohio
Fellows, Ambrose B.; W; M; 5; Son; Single; Attended school during the census year; b. Iowa; Both parents b. Ohio
Fellows, Levi L.; W; M; 6/12; b. Dec. 1879; Son; Single; b. Iowa; Both parents b. Ohio
The exact site of Bartholomew's birth has yet to be determined, since the town and county where he is said to have been born were not founded until several years after his birth. The region around what would first be called "Shibboleth" was a summer home to the Sioux and Winnebago nations. The first white settlement was made at Shibboleth in 1853 (five years after Bartholomew's birth) at the confluence of the Winnebago River and Calmus Creek. The town later had several names: Shibboleth, Masonic Grove, and Masonville, until the name Mason City was adopted in 1855, in honor of a founder's son, Mason Long. The county of Cerro Gordo, where Mason City is located, was established in 1851.