Argo (1851-1901) 
Armenian (1861-1865) 
Ashford (1856-1857) 
Barth (DPO) 
Blackhawk (1948-1958) 
Blackoak (1884-1886) 
Bluffville (1849-1867) 
Chadwick (1886-Date) 
Cherry Grove (1836/1861) 
Daggets (1887-1906) 
East Plum River (1843-1846) 
Elkhorn Grove (1848-1900) 
Fair-Haven (1850-1906) 
Hitt (1884-1900) 
Ideal (1891-1902) 
Jacobsville (1852-1852) 
Johnson's Creek (1868-1882) 
Keltner (1892-1904) 
Lanark (1861-Date) 
Milledgeville (1844-Date) 
Mount Carroll (1845-Date) 
Nursery (1885-1901) 
Panama (1840-1842) 
Polsgrove (1856-1903) 
Proving Ground (1939-1948) 
Rock Creek (1848-1883) 
Sandville (1865-1865) 
Savana (1835-Date) 
Shannon (1861-Date) 
Spring Valley (1853-1861) 
Thomson (1865-Date) 
Tysonville (1844-1845) 
Wacker (1894-1906) 
Zion (1881-1905) 

   [Source: Used with permission from Jim Forte at www://postalhistory.com]