Iowa became a territory in 1838 and a state in 1846. The state of Iowa conducted statewide census in 1847, 1849, 1854, 1856, 1859, 1862, 1865, 1867, 1869, 1873, 1875, 1880, 1885, 1895, 1905, 1915 and 1925.
The Census of Iowa has been archived by the New York Public Library and University of Minnesota (for HathiTrust) for the years 1856, 1867, 1869, 1873, 1875, 1880, 1885, 1905, and 1915 The list of these archived census publications can be found at HathiTrust
The Census of Iowa has also been archived by the University of Illinois at Urbana-Champaign (for HathiTrust) for the years 1859, 1895, and 1925. The list of these archived census publications can be found at HathiTrust
An early “county” census of the Wisconsin Territory (Dubuque County - lands north of the modern Quad Cities, Demoine County - lands south of the modern Quad Cities).
Iowa Historical Census by 
The First Census of the Original Counties of Dubuque and Demoine taken in July, 1836 by 
