Side A: Marcellus F. Cowdery, Sandusky’s first Public School superintendent, encouraged William D. Curtis to formulate a chalk that did not break easily or scratch chalkboards. Curtis conducted experiments in his kitchen and, using gypsum and limestone deposits from Sandusky Bay, created sticks of pure white, processed chalk. In the late 1860s, he and his brothers-in-law, Marcellus and John S. Cowdery, began producing the chalk from their family home. In 1890, John Whitworth, Curtis’s son-in-law, helped finance the incorporation of The American Crayon Company. The company pioneered high quality art supplies, including wax color crayons and Prang watercolors, used in schoolrooms around the globe. Sandusky’s American Crayon factory that stood at 1706 Hayes Avenue for more than a century, closed production in 2002 and was later demolished.