The first state capital of Missouri and over one hundred other historic buildings are located in the district.

[1] The original listing included the separately NRHP-listed First Missouri State Capitol Buildings and the Newbill-McElhiney House.

[1][3] In 1987 the district was increased to include a Greek Revival specialty store building at 1000 S. Main Street, with a 1.3-acre (0.53 ha) area.

This included the St. Charles Odd Fellows Hall, the Old City Hall, a post office, and other buildings in late 19th and 20th Century Revivals, Greek Revival, and Late Victorian architectural styles.

[1][4] In 1996, the district was further increased by 9 acres (3.6 ha) to include 41 more contributing buildings on the 100, 200, and 300 blocks of N. Main Street.