Built in 1846 by early Cedarburg businessmen Frederick Hilgen and William Schroeder, this cream city brick building served as a retail outlet for the flour and feed mill across the street, the Cedarburg Mill, and also housed mill employees. For the next several decades it operated as the mill store for the five story stone gristmill built in 1855, while the feed mill grounds included stables and a barn for the business's horses. In the late 1800's, the lower level was converted into a tavern, and in 1931 the Riverside Cafe opened in a small stand alone building to the east. After alterations under several proprietors, Walter Barth bought the property before United States' entry into World War II and opened Barth's Tavern, which later became Barth's Cocktail Bar Restaurant, a community institution. In the 1960s Palmer Krueger, Barth's son-in-law, took over the diner, and the family business continued for 60 years before closing in 2001. After another decade of changes, Mal and Jill Hepburn purchased the building and in 2015 donated it to the Cedarburg Landmark Preservation Society for use as a Cedarburg History Museum and Visitor Center for the Cedarburg Chamber of Commerce.