Northwood glass was made by the H. Northwood Co., founded in Wheeling, West Virginia, in 1901 by Harry Northwood. He worked for the Hobbs-Brockunier and LaBelle firms in the 1880s before operating his own glass plants in Martins Ferry, Ohio, and Ellwood City and Indiana, Pennsylvania. At the Wheeling factory, Harry Northwood and his brother Carl manufactured pressed and blown tableware and novelties in many colors that are collected today as custard, opalescent, goofus, carnival, and stretch glass. Pieces made between 1905 and about 1915 may have an underlined N trade mark. In 1908, Northwood began producing carnival glass with a pattern of grapes, one of its earliest patterns. Harry Northwood died in 1919, and the plant closed in 1925.