Monmouth Pottery Company started working in Monmouth, Illinois, in 1892. The pottery made a variety of utilitarian wares. It became part of Western Stoneware Company in 1906. The maple leaf mark was used until 1930. If Co. appears as part of the mark, the piece was made before 1906. Monmouth's stoneware animal figurines and other small items were not stamped with the company's maple leaf mark.