Samuel A. Barnum enlisted as a Private on 25 April 1861 at the age of 21. Enlisted in Company "I", 3rd Infantry Regiment Ohio (3 months' service) on 30 April 1861. Mustered out Company "I", 3rd Infantry Regiment Ohio on 22 August 1861. Enlisted as a Private in Company "E", 34th Infantry Regiment Ohio on 25 November 1861. See the entry for his younger brother, Albert Preston Barnum, for more details about the wartime service of both of these units.
In the 1880 US Census for District 194, Granada, Nemaha County, Kansas, the family of Samuel A. Barnum was enumerated as follows:
Household #169; Family #184
Barnum, Samuel; W; M; 39; Married; Farmer; b. Ohio; Mother b. Maine
Barnum, Bell; W; F; 38; Wife; Married; Keeping house; b. Pennsylvania; Both parents b. Pennsylvania
Barnum, Hattie B.; W; F; 3; Daughter; Single; b. Illinois; Father b. Ohio; Mother b. Pennsylvania
In the 1900 US Census for District 26, Horton, Brown County, Kansas, the family of Samuel A. Barnum was enumerated as follows:
Household #58; Family #58
Barnum, Samuel; Head; W; M; b. Nov 1840; 60; Married 30 years; b. Ohio; Father b. Maine; Mother b. Vermont [Note: parents' birthplaces are reversed]; Undertaker; Employed full year; Can read, write and speak English; Owns non-farm home free of mortgage
Barnum, Bell; Wife; W; F; b. Aug 1841; 58; Married 30 years; Mother of 1 child; 1 child living; b. Pennsylvania; Father b. New Jersey; Mother b. Pennsylvania; Can read, write and speak English
Barnum, Hattie B.; Daughter; W; F; b. Sept 1877; 22; Married 3 years; Mother of 1 child; 1 child living; b. Illinois; Father b. Ohio; Mother b. Pennsylvania; Can read, write and speak English
Garden [s/b Gordon], Emory C.; Son-in-Law; W; M; June 1873; 26; Married 3 years; b. Ohio; Both parents b. Ohio; Teacher; Can read, write and speak English
In the 1910 US Census for Kansas City Ward 2, Wyandotte County, Kansas, the family of Samuel A. Barnum was enumerated as follows:
Household #40; Family #41
Barnum, Samuel A.; Head; M; W; 68; 1st Marriage; Married 40 years; b. Ohio; Both parents b. Maine; Speaks English; Conductor; Freight; Wage earner; Employed full year; Can read and write; Owns non-farm home free of mortgage
Barnum, Belle; Wife; F; W; 67; 1st Marriage; Married 40 years; b. Pennsylvania; Father b. New Jersey; Mother b. Pennsylvania; Speaks English; No trade or Profession; Can read and write
Mathews, Harry L.; Boarder; M; W; 31; 1st Marriage; Married 8 years; b. Kansas; Father b. New Jersey; Mother b. Pennsylvania; Speaks English; Conductor; Freight; Wage earner; Employed full year; Can read and write
Mathews, Minnie M.; Boarder; F; W; 28; 1st Marriage; Married 8 years; b. Illinois; Father b. New York; Mother b. Ohio; Speaks English; No trade or Profession; Can read and write