In 1860, Thomas M. Armstrong, the son of Scottish-Irish immigrants from Derry, joined with John D. Glass to open a one-room shop in Pittsburgh, Pennsylvania, carving bottle stoppers from cork by hand. Their first deliveries were made in a wheelbarrow. Armstrong was a business pioneer in some respects: he branded each cork he shipped as early as 1864, and soon was putting a written guarantee in each burlap bag of corks he shipped from his big new factory. The company grew to be the largest cork supplier in the world by the 1890s. The company incorporated in 1891.