[5] The city was named after Mount Vernon, the estate of George Washington.

[6] A post office called Mount Vernon has been in operation since 1846.

[7] Lawrence County Courthouse and Old Spanish Fort Archeological Site are listed on the National Register of Historic Places.

[8] According to the United States Census Bureau, the city has a total area of 3.87 square miles (10.02 km2), all land.

34.8% of all households were made up of individuals, and 16.6% had someone living alone who was 65 years of age or older.

33.8% of all households were made up of individuals, and 16.3% had someone living alone who was 65 years of age or older.

[12] The Mount Vernon High School "Lady Mountaineers" won the Missouri Class 3A girls basketball state championship in 2010 and 2012.

[14] In October, the city hosts "Apple Butter Makin' Days", an annual crafts and food festival.