Israel served as a Private during the War of 1812. He enlisted on 10 September 1814 in Captain Henry Per Lee’s Company of the New York Militia and was honorably discharged on 5 December of that same year.
In the 1850 US Census for Shandaken, Ulster County, New York the family of Israel M. Barnum was enumerated as follows:
Dwelling #257; Family #264
Israel M. Barnum, 56, M, Farmer, b. New York
Mary Barnum, 57, F, b. New York
Israel R. Barnum, 26, M, Farmer, b. New York
Jonathen Barnum, 24, M, Farm hand, b. New York
Zadocke Barnum, 17, M, Farm hand, b. New York
Noah Barnum, 15, M, Farm hand, b. New York
Jane Barnum, 12, F, b. New York, Attended school within the year
Warren Barnum, 9, M, b. New York, Attended school within the year
Annette Barnum, 7, F, b. New York, Attended school within the year
Jonathen Dean, 25, M, b. New York, Married within the year
Mary A. Dean, 20, F, b. New York, Married within the year [N.B., Israel's daughter Mary Ann].
In the 1860 U. S. Census for Dunn, Dunn County, Wisconsin the family of Israel M. Barnum was enumerated as follows:
Burnam, Israel, age 65, Farmer, b. New York
Burnam, Mary A., age 65, b. New York
Burnam, Hirum, age 34, b. New York
Burnam, Warren, age 20, b. New York.
Gravestone inscription: Pvt. 1 N.Y. Mil. War of 1812.