The original Hallgarten & Company was an investment bank based in New York City founded in 1850 by Lazarus Hallgarten.Originally it was focussed on gold dealing and foreign exchange. It was part of the circle of prominent firms known as "Our Crowd" that were linked by family ties (and included the Seligmans and the Lehmans). The firm became one of the most important investment banks in the rapidly evolving US economy. The firm became a member of the New York Stock Exchange on January 1, 1881.
It also was an important player internationally with offices at various times in London, Paris, Berlin, Amsterdam and Rome.
After the 1960s the firm became less important, though it was the first NY Stock Exchange member to apply to become a member of the London Stock Exchange (it was rejected as it was a corporate at the time all LSE firms were partnerships).
The firm merged with several other firms becoming eventually Moseley, Hallgarten Estabrook & Weeden. The crash of 1987 badly damaged the firm's finances and it ceased trading, with Weeden being rescued from the wreckage by its principals.
Hallgarten & Company was refounded in 2003 in New York as an equity research house and corporate advisory firm. It specialises in services to the mining and energy industries.
Somewhat ironically the new firm established offices at 44 Wall Street in 2004, only to discover that the building had long been the headquarters of the "old" Hallgarten & Co. from 1941.
A history of the firm's first 100 years can be found here: