In 1830, Sennitt lived in Macon County, Illinois with two other people. He served as a private in a company from Decatur in the Black Hawk War. By 1840, he was between 30 and 40 years old and still resided in Macon County.
U.S. Census Office, Fifth Census of the United States (1830), Macon County, IL, 123; U.S. Census Office, Sixth Census of the United States (1840), Macon County, IL, 15; Perry A. Armstrong, The Sauks and the Black Hawk War, with Biographical Sketches, Etc. (Springfield, IL: H. W. Rokker, 1887), 689.