Northampton and surrounding areas of the Lehigh Valley are rich in limestone, which is commonly used in the production of cement. The Atlas Portland Cement Company, based here from 1895 to 1982, was the world's largest cement company at one time, and one of dozens in the area. It produced some 8 million barrels of cement for construction of the Panama Canal, most of what was used on the project. Atlas was bought by another company in 1980 and ceased operation here in 1982; its last smokestack here was demolished in 1993. Today technology and automation mean that the cement industry can manufacture a great amount of product with 150-200 workers, rather than the thousands who worked in these plants earlier in the 20th century.