Brown Brothers Harriman & Co. (BBH) is the oldest and one of the largest private investment banks in the United States.

[5] Brown Brothers Harriman provides advisory, wealth management, commercial banking, and investor services for corporate institutions and high-net-worth individual clients.

[2][7] After immigrating to Baltimore in 1800 and building a successful linen mercantile trading business,[3][4][8] Alexander Brown and his four sons co-founded Alex.

[16] In 1930s the company acted as a U.S. base for the German industrialist Fritz Thyssen, who helped finance Adolf Hitler.

W. Averell Harriman was the ambassador and statesman responsible for the relationship between Winston Churchill and Franklin Roosevelt during World War II.