Buildings at 207–209 South Main St.

Digel Block was a historic commercial building located at Hannibal, Marion County, Missouri. It was built in 1901, and was a two-story red-brick building. It featured an ornamental parapet screening a flat roof.: 54–55  It has been demolished. It was added to the National Register of Historic Places in 1986.

Mark Twain Hotel is a historic hotel building located at Hannibal, Marion County, Missouri. It was designed by Barnett, Haynes & Barnett and built in 1905. It is a four-story, Renaissance Revival style steel-frame structure with a granite foundation and beige pressed-brick exterior. The annex was built in 1918. It features semicircular arches over the main door and adjacent windows.: 50–51  It was then added to the National Register of Historic Places in 1986.

Holmes–Dakin Building is a historic commercial building located at Hannibal, Marion County, Missouri. It was built in 1894, and is a two-story brick structure with a coursed rubble foundation and a flat roof. It features a corbelled brick frieze with matching corbelled parapet, capped by a stone molding. It originally housed a cigar factory.: 46–47  It was added to the National Register of Historic Places in 1986.

Davidson Building was a historic commercial building located at Hannibal, Marion County, Missouri. It was built between 1903 and 1905, and was a two-story Romanesque Revival style building. It had a three-bay rock-faced ashlar facade and party walls. It featured arched windows with radiating voussoirs.: 44–45  It has been demolished. It was added to the National Register of Historic Places in 1986.

Robert Elliott's Wholesale Grocery is a historic commercial building located at Hannibal, Marion County, Missouri. It was built about 1886, and is a two-story brick structure. It features semicircular arches with fanlight tops on the first floor, upper windows with segmental arches, and an applied cornice, possibly metal.: 58–59  It was added to the National Register of Historic Places in 1986.

Green Double House is a historic duplex home located at Hannibal, Marion County, Missouri. It was built in 1857–1858, and was a one-story, "raised cottage" or the "double gallery" clapboard structure on a completely exposed squared rubble basement. The house was divided into two residences.: 56–57  It has been demolished. It was added to the National Register of Historic Places in 1986.

Hafner Grocery Warehouse is a historic commercial warehouse located at Hannibal, Marion County, Missouri. It was built about 1910, and is a three-story brick structure on a concrete foundation. It features seven bays of segmental-arched windows and a corbelled parapet.: 48–49  It was added to the National Register of Historic Places in 1986.

Broadway District is a national historic district located at Hannibal, Marion County, Missouri. The district encompasses 28 contributing buildings in the central business district of Hannibal. It developed between about 1866 and 1934, and includes representative examples of Italianate, Classical Revival, and Art Deco architecture. Notable buildings include the Lakenan Building (c. 1866), Kresge Building (1931), Second Farmers and Merchants Bank (c. 1910), Sproul-Cash Store (1901), Hannibal Trust Company (1909-1910), Hickman Block (c. 1865), and Robinson Brothers (c. 1894).: 18–27  It was listed on the National Register of Historic Places in 1986.

Ebert-Dulany House is a historic home located at Hannibal, Marion County, Missouri. It was built about 1865, and is a two-story, Second Empire style brick dwelling. It has a mansard roof and sits on a rock-faced ashlar foundation. It features a large bracketed hood above once sheltered a balcony and a wide bracketed frieze that runs below the modillioned cornice. The house was restored in the late-1980s.: 2  It was added to the National Register of Historic Places in 1983. It is located in the Maple Avenue Historic District.

Hannibal Old Police Station and Jail, also known a City Hall, is a historic police station and jail located at Hannibal, Marion County, Missouri. It was built in 1878–1879, and is a two-story, eclectic late Victorian style brick building on a granite foundation. It features two octagonal towers of different heights and a complex roof defined by a heavy bracketed cornice.: 2  It was added to the National Register of Historic Places in 1979. It is located in the Central Park Historic District.

Standard Printing Company, also known as the Hayward Grocery Company, is a historic commercial building located at Hannibal, Marion County, Missouri. It was built in 1879, and is a three-story, nine bay by ten bay, Italianate style brick structure. It features segmental arched windows, a lavish bracketed and modillioned cornice, and a storefront with intact cornice and iron pilasters.: 38–39  It was added to the National Register of Historic Places in 1986.

North Main Street Historic District is a national historic district located at Hannibal, Marion County, Missouri. The district encompasses 27 contributing buildings in the central business district of Hannibal. It developed between about 1852 and 1935, and includes representative examples of Italianate and Beaux Arts architecture. Notable buildings include the Lone Building (1853), Brown's Drug Store (1858), Old Central Hotel (1868-1874), Old Schultz Furniture Store (c 1863), Original Farmers and Merchants Bank (1876), Jameson Hawkins Row (1852), Bernice Gano Tavern (c. 1935), and A. W. Lamb Building (c. 1870-1875).: 28–37  It was listed on the National Register of Historic Places in 1986.