During the nineteenth century, Rockport was a major supplier of lime to East Coast markets, with kilns that converted limestone from fifteen local quarries into lime for mortar and finish plaster. The burned lime was packed into wooden casks and shipped by schooner, and in 1843 all one hundred lime cargos came from kilns in Rockport, Camden, and Thomaston. In 1859, the industry was worth $100,000 and shipped 156,500 casks. Built of granite and field stone with interiors lined with fire brick, the kilns were enclosed by large wooden flat-roofed sheds, and some were topped with iron stacks made of boiler plate. Most were wood-burning, except for the triple “Pets,” which burned soft coal. Limerock was loaded at the top from a trestle along the back, fires were fed continuously day and night except for a half hour before the kiln was drawn every four hours, and partially burned lime was hauled to dumps along the Goose River. A disastrous fire in 1907 struck as cement was beginning to replace lime in building construction, and although the industry continued for a few more years, it never fully recovered. Through the efforts of Mr. Ambrose Cramer, these kilns, the last surviving evidence of Rockport’s industrial past, were declared an historic site in 1970. Under the direction of his widow, Mary Cramer, the lime kiln restoration committee was formed in 1976 to restore and stabilize the kilns, and in 1983 a matching grant permitted preservation of the unusual triple kilns so that the interior can be seen.