J.S. Morgan & Co.
J.S. Morgan & Co. was a merchant banking firm based in London and New York City founded by Junius S. Morgan, father of J. Pierpont Morgan, and George Peabody in 1854.
J.S. Morgan & Co. was originally called Peabody, Morgan & Co. and the name was changed when Junius assumed control of the firm in 1864 (when George retired fully) and brought his son J. Pierpont Morgan into the firm to head its New York office.
J.S. Morgan is considered a predecessor of J.P. Morgan & Co. which was founded in 1871 as Drexel, Morgan & Co. and is today part of JPMorgan Chase.