Formed November 16, 1820 (23rd county)
Ralls County (10,355), New London (940)
The stone Greek Revival structure, built in 1858, is on the square at Main Street, 3rd, Ralls, and 4th streets. United States Highway 61 Business is Main Street in the town. The courthouse was remodeled and enlarged in 1935 and renovated in 2006. Henry C. Wellman and Nathan S. Dimmitt were the building architects. The building features columns and a small domed tower. There were 1822 and 1835 courthouse previously in New London, the only county seat. Ralls County was created on November 16, 1820 from parts of Howard and Pike counties as the 23rd county. The county is named for Legislator Daniel Ralls. The county seat is named for London, England.
Ralls County government consists of a sheriff, an administrator, an attorney, a collector, a coroner, an assessor and a clerk (executive). It has 3 Commissioners (legislative.) One Circuit Court Judge serves Ralls, Marion, and Monroe counties and One County Court Judge and a court clerk serve Ralls County (judicial.) The county is in northeast Missouri. Saint Louis, Missouri is southeast and Kansas City, Missouri is west of the county. It sits on the Mississippi River border with Illinois. The county center is 7.5 miles Southwest of New London nearer Center. The county is surrounded clockwise by Marion County and Illinois and Pike, Audrain, and Monroe counties.
The area of the county is 471 square miles. It is 91 out of 115 in the state. It ranks 84 out of 115 in population in the state. It has a density of 22.0 persons per square mile making it 73 out of 115 in the state. Ralls County has 26.0% of its population in its incorporated areas. United States Highways 24/36 clip the northwest corner of the county from entering from Marion County, north, and reentering to Marion County, west. United States Highway 61 goes north to south from Marion County to Pike County. The county is shaped like a small letter r. New London is in the northeast quarter of the county. New London is the county seat and the largest city. It is 9.1% of the county population. This county is in the Hannibal Micropolitan Statistical Area.
Center
New London
Perry
Rensselaer
Hannibal
Monroe City
Vandalia