According to the Missouri State Archives, the earliest census taken in Missouri was actually of the Missouri Territory in the years 1814 and 1817, and only free white males were counted. In the year 1821, Missouri was granted statehood, and a state census was taken that year. Then, from 1824 and every four years after that through 1876 (except for 1872), a state census was taken throughout Missouri. Meanwhile, the decennial federal census, which began in 1790, did not begin in Missouri until 1830, but neither Springfield nor Greene County was listed until the 1840 census. Greene County was legally formed in 1833, and Springfield, the county seat, was incorporated in 1838. Boundaries were to change for both political units over the years, with the original Greene County parceled out to form other counties until the 1860 census which generally reflects present-day boundaries. Springfield and North Springfield, two separate entities, were united as Springfield in 1887, and there have been other annexations since then to the present day.
Stewart, Byron, "Springfield and Greene County, Missouri Census Information, 1836-2010" (2011). Articles by MSU Libraries Faculty. 129.