Numerous shipyards developed along Port Jefferson's harbor and the village's shipbuilding industry became the largest in Suffolk County. A common misconception is the belief that the village was as a major whaling port. This is not supported by Government documents used to compile the two definitive references on the American Whale fishery. These two works list every vessel and every voyage undertaken by American whaling vessels from colonial days until the 1920s, none of which began or ended at Port Jefferson. However two whaling vessels were built for New Bedford at Port Jefferson in 1877 (ship "Horatio" and bark "Fleetwing"), and a Port Jefferson built schooner ("La Ninfa") was later converted into a whaling vessel at San Francisco. Port Jefferson's main role as a port in the 19th Century was to build and support vessels engaged in the coastal freighting trades. Many of Port Jefferson's remaining homes from this period were owned by shipbuilders and captains. This includes the Mather House Museum, a mid-19th century home once owned by the Mather shipbuilding family that now serves as the center of a museum complex and headquarters for "The Historical Society of Greater Port Jefferson".