David O. Saylor was born the son of Samuel and Margaret Saylor on October 20, 1827. His father owned and operated a general country store in Butztown, Pennsylvania. While David received his schooling locally in the area, he assisted his father in running the store, and when he became of age he inherited the business. David, in search of other opportunities, sold the store in 1863, moved to Allentown, and started selling produce in the markets there, from the back of his truck. In the winter of 1866, he was about to enter the slate business but was brought to the attention of the cement business by an aquaintance, Esias Rehrig. In the spring of 1867, David O. Saylor, Esias Rehrig, and Adam Woolever purchased 30 acres of cement producing property in Coplay, Pennsylvania. It was here the Coplay Cement Company received its business charter, and Saylor discovered the process that enabled portland type cement to be produced in the United States. Saylor patented his process and received the highest award for quality at the Centennial Exhibition in Philadelphia in 1876. The Coplay Cement Company was the sole producer of portland cement in the United States until 1885. David O. Saylor died July 21, 1884, but the company kept expanding after his death. The Coplay Cement Company expanded to a size of three mills in Coplay alone. In 1966, Coplay Cement aquired Nazareth Cement Company which nearly doubled its capacity. Giant Portland Cement at Egypt and the Penn-Dixie facility were also later purchased by Coplay Cement. All of these companies were located in the Lehigh Valley area. In 1976, Coplay Cement was aquired by the Essroc Company which still produces Saylorís portland cement today. The cement plant located in Coplay is no longer in operation, but the continuous vertical kilns of mill B still remain today, and serve as the David O. Saylor Cement Museum commemorating the birthplace of the United States cement industry.