Fourth an Locust, looking west on Locust. The Mermod, Jaccard & Co. sign on the righthand building at 401-403 North Fourth dates this picture after 1874. The Union Sign Works, whose own sign can be detected midway down the south side of Locust, was listed at that address in the City Directory of 1878. The north side of Locust has changed very little over the years, some of its building being among the oldest in downtown St. Louis and presenting almost the same view today as when this picture was taken about 1880. Emil Boehl made the above photo of an 1856 drawing of Locust, west from Fourth, for its historic significance. The three-story building, left foreground, is the Mercantile Library and Hall, scene of the constitutional convention which kept Missouri in the Union. A London newspaper described it as the finest hall in America. The same scene below had changed somewhat when Boehl got around to photographing the street 20 years later.