1860, December 20 South Carolina, rapidly followed by six other southern states, secedes from Union in reaction to election of Lincoln, who opposes extension of slavery into western territories. These states organize the Confederate States of America.
Pettis County Missouri (Vacant / Not In Use) has 1 places on the National Register of Historic Places.
Some of the country's most noteable architects helped create the Pettis County places including Henry Jones and Robert Barnhart. Prominent architectural styles found in Pettis Country are Georgian and Italianate.