 In 1931, the firm merged with Harriman Brothers & Company to form Brown Brothers Harriman & Co., which today is the oldest, and one of the largest, private banks in the United States.In 1827, when bad management almost reduced the Mechanics Bank, of which he was the principal founder, to insolvency, Brown stepped in to become its president, and turned the bank around in a short time.George Brown had a prominent role in the founding of the Baltimore and Ohio Railroad (B&O), the first common carrier railroad in the U.S. On February 12, 1827, he hosted a meeting at his Baltimore home for 24 leading merchants, where Philip E. Thomas joined Brown in advocating the formation of a railroad to make Baltimore competitive with other eastern seaboard ports.