https://en.wikipedia.org/wiki/Brown_Brothers_Harriman_%26_Co.

Brown Brothers Harriman & Co. (BBH) is the oldest and one of the largest private investment banks in the United States.[3][4] In 1931, the merger of Brown Brothers & Co. (founded in 1818) and Harriman Brothers & Co. formed the current BBH.

Brown Brothers Harriman is also notable for the number of influential American politicians, government appointees, and Cabinet members who have worked at the company, such as W. Averell Harriman, Prescott Bush, Robert A. Lovett, Richard W. Fisher, Robert Roosa, Alan Greenspan[5] and Scott Bessent.

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Much, much, much more at the Wikipedia link. Nexus of power and wealth, the names of founding partners perhaps more important than those who invested with them.

Spun off commercial banking which became through mergers Drexel Burnham Lambert.

my aunt and uncle worked for him for decades.