Gerard Holsman Coster was the son of John Gerard Coster. Apparently he carried on the family banking tradition for the letter discusses major financial transactions in the planning.  Coster lived in Europe, principally in Paris.  Historic item.  John Gerard Coster (August 1762 – August 8, 1844) was a Dutch-American merchant who served as president of the Bank of the Manhattan Company. Coster was born in August 1762 in Haarlem, Holland. Coster came to the United States from Haarlem in the Netherlands shortly after the Revolutionary War and founded the family fortune with his brother through the mercantile firm, "Henry A. & John G. Coster". They became owners of numerous vessels and traded with the East and West Indies, and exported American commodities to Europe.

In 1813, he was made a director of Bank of the Manhattan Company, which had been founded by Aaron Burr in 1799. In 1825, Coster was made president of the Manhattan Company, succeeding Henry Remsen upon his death. Coster was also a director of the Phoenix Insurance Company for many years.