A monumental granite bank in the classical manner, its long Locust Street front given over to a colonnade of tall fluted Ionic columns carrying a dentiled entablature and a balustraded parapet, with a low attic story above. Round-arched windows stand behind the columns, and the name MERCANTILE TRUST COMPANY is cut into the granite base at the corner. The building turns Eighth Street with a plain granite pier framing a columned entrance. Its exposed side wall is faced in brick and terra-cotta panels salvaged from the neighboring Ambassador Building; the original mansard roof is long gone.
The Mercantile Trust Company built its headquarters at the northeast corner of Eighth and Locust Streets in 1904, to a Beaux-Arts design by the St. Louis architect Isaac Taylor. Taylor's original building — smaller, and crowned by a mansard roof — was repeatedly enlarged and altered: it lost the mansard, gained a full story and additional bays at each end, and in the 1960s took on yet another story in a mid-century Modernist manner. A 1990s renovation added a stainless-steel entrance canopy and refaced the exposed party wall with brick and terra-cotta panels salvaged from the Ambassador Building, demolished next door. Mercantile grew into one of the city's largest banks before a series of mergers folded it into Firstar and, by 2000, U.S. Bank. The building later stood vacant, offered for redevelopment.
