In the post-Civil War Gilded Age, J. & W. Seligman & Co. invested heavily in railroad finance, in particular acting as broker of transactions engineered by Jay Gould. They underwrote the securities of a variety of companies, participating in stock and bond issues in the railroad and steel and wire industries, investments in Russia and Peru, the formation of the Standard Oil Company, and shipbuilding, bridges, bicycles, mining, and a variety of other industries.