Henry Underwood was born in New York and lived in Albany. He worked as a supply agent. He is mentioned in a letter from WSJ to FMS on March 4, 1860: "I believe I wrote you that I was going to Albany. I spent Monday night with Fred who I found quite well. Mrs. Wharton & John were both with him. I went down partly to see Henry Underwood and partly to talk with Mr. Schoolcraft about the banking or real estate business." (18600304WSJ_FMS1) Underwood was WHS's personal secretary from 1851-1852. He married Eliza Catlin in 1844. https://www.geni.com/people/Henry-Underwood/6000000001727286821