 Soon after, Abraham Seligman opened a bank in New York City, followed by the London branch, established by Isaac and Leopold Seligman, and the Paris branch, established by William Seligman.In the post-Civil War robber baron era, the firm invested heavily in railroad finance, in particular acting as broker of transactions engineered by Jay Gould.Among the companies in the Seligman portfolio were The Missouri Pacific, the Atlantic and Pacific, the South Pacific, and the Missouri–Kansas–Texas railroad companies.