New technology and fresh perspectives are jumpstarting efforts to assemble exhaustive lists of works by 19th-century American painters, sometimes in progress for decades. Next month a consortium of museums interested in the Massachusetts maritime painter Fitz Henry Lane (1804-65) will introduce a website, fitzhenrylaneonline.org, documenting about 320 paintings, drawings and prints at various institutions. Much of the material is being drawn from the Cape Ann Museum, in Mr. Lane’s hometown, Gloucester, Mass., and images on the website will be linked to infrared paint analyses, biographies of Mr. Lane’s clients, newspaper ads for his suppliers, maps of harbors where he sketched and portraits of owners of the ships moored there.