| Year |
County and Date |
| 1812 |
October 1: Cape Girardeau, New Madrid, St. Charles, St. Louis, and Ste. Genevieve |
| 1813 |
August 21: Washington |
| 1816 |
January 23: Howard |
| 1818 |
December 8: Jefferson
December 11: Franklin, Wayne
December 14: Lincoln, Madison, Montgomery, Pike
December 17: Cooper
|
| 1820 |
November 16: Boone, Chariton, Cole, Lillard (now Lafayette), Perry, Ralls, Ray
November 26: Callaway, Gasconade, Saline
|
| 1821 |
December 19: St. Francois
December 28: Scott
|
| 1822 |
January 2: Clay |
| 1826 |
December 15: Jackson
December 23: Marion
|
| 1829 |
January 22: Randolph
January 23: Crawford
|
| 1831 |
January 6: Monroe |
| 1833 |
January 2: Carroll, Clinton, Greene, Lewis
January 5: Morgan, Ripley, Warren
January 19: Pulaski
January 26: Pettis
|
| 1834 |
December 13: Rives (later Henry), Johnson |
| 1835 |
January 2: Shelby, Stoddard
January 3: Benton
January 5: Barry, Polk
March 3: Van Buren (later Cass)
|
| 1836 |
December 16: Clark
December 17: Audrain
December 29: Caldwell, Daviess
|
| 1837 |
January 6: Linn, Livingston, Macon, Taney
February 6: Miller
|
| 1838 |
December 31: Buchanan, Newton, Platte |
| 1841 |
January 29: Adair, Andrew, Bates, Dade, Grundy, Jasper, Kinderhook (later Camden), Niangua (later Dallas), Nodaway (later Holt), Osage, Ozark (later Decatur, then Ozark again), St. Clair, Scotland, Shannon, Wright
|
| 1845 |
February 14: Atchison (defined as Allen in 1843), Cedar, Dunklin, Gentry, Harrison, Hickory, Knox, Lawrence, Mercer, Mississippi, Moniteau, Nodaway, Oregon, Schuyler, Sullivan (defined as Highland in 1843), Texas (defined as Ashley in 1843)
February 25: DeKalb, Reynolds
February 28: Putnam
|
| 1846 |
December 18: Dodge (abolished and added to Putnam in 1853) |
| 1849 |
February 24: Laclede
February 27: Butler
March 3: McDonald (defined as Seneca in 1847)
|
| 1851 |
February 10: Dent, Stone
February 19: Pemiscot
March 1: Bollinger
|
| 1855 |
February 27: Vernon
March 2: Maries
March 3: Webster
December 12: Barton
|
| 1857 |
February 17: Iron
March 2: Howell
October 29: Douglas
November 13: Phelps
|
| 1859 |
March 8: Christian
March 10: Carter
|
| 1861 |
February 8: Worth |
| 1876 |
August 22: St. Louis City separated from St. Louis County |