The Grant’s Drug Store Building, also known as the The Pilaster House (1836) is one of the oldest buildings surviving in Hannibal and a fine example of Greek Revival Architecture. The interior timbers were cut and fitted together in Cincinnati, Ohio, then dissembled and shipped by steamboat to its present destination. The structure was originally headed to Marion City, North of Hannibal, but flood waters prevented delivery of the members, and the decision was made to use them at Hannibal. The building contractor who erected and finished the building was James Brady, who would later become the first Mayor of Hannibal.
Dr. Orville Grant, his wife and her mother lived in the upstairs rooms of the house in the 1940s. Dr. Grant had an office and drug store on the first floor. In late 1846 John Marshall Clemens, father of Samuel L. Clemens, the future Mark Twain, was bankrupt and had to move his family out of their home across the street. The Grants accepted the Clemens family into their second floor living quarters, where they shared the space. Jane Clemens, the widow of John Marshall Clemens was eventually able to raise funds to move her family back into their own home, now known as the Mark Twain Boyhood Home. Although their stay here was brief, both as a residence for the Clemens family in Hannibal, and as a source and setting for several Mark Twain stories, the Pilaster House has historical significance that is shared with a worldwide visiting audience.
The floors of the Pilaster Building have been sagging, and settling is acutely evident throughout the building, from roof ridge to foundations. Many cracks have appeared on the interior walls and one of the walls waves in and out. The settlement could be from settling soil around the foundations, but in addition, much of the wood framing in the crawl space beneath the building has rotted from repeated flooding and there is evidence of termite infestation that could be widespread and hidden beneath the interior walls.