[2] Foreseeing the needs of electrification, Hayden made his fortune by investing in copper mining.

The new investment firm prospered, expanding from its Boston base to open a New York City branch in 1906.

[1] In 1970, the prestigious Hayden, Stone found itself in financial trouble along with many other large securities firms.

At one point, the firm was considered to be the third largest "wire-house" in the country behind only Merrill Lynch and Bache & Co.

The following is an illustration of the company's major mergers and acquisitions and historical predecessors (this is not a comprehensive list):[4] American Express(est.