Salad Plate, Crown Potteries, U.S.A. Crown Potteries made high quality porcelain and semi-porcelain. They were in business from 1882 until 1954. This plate measures 7 1/4 in diameter. Other than slight crazing, it is in very good condition. It has the Crown Potteries Co. Made in U.S.A. mark. It is also marked Ovenproof .