Mortality schedules were created during specific census years when the census taker inquired about persons who had died in the twelve months immediately preceding the enumeration. This occurred during the years of 1850-1885, and includes the 1850, 1860, 1870, 1880, and 1885 Federal census. Illinois did not take the 1885 Federal census, so there are no mortality schedules for that census from Illinois. Unfortunately, the 1870 census mortality schedules are missing for all counties in Illinois alphabetically from Adams to Kankakee. This means there is no surviving copy of the 1870 mortality schedules for DeKalb County Illinois. That leaves only three schedules which survived, the 1850, 1860, and 1880. All there of those can be found on this website.