The Iowa "Roster and Records" says Brownell mustered out with his company after their three years were up in November 1864. But Wilson's letter and other letters from Wilson's companions say Brownell was with them at Camp Ford. I believe his Compiled Record shows he died at Camp Ford, but need to re-check. No one seems to have filed for a pension in his name.

Brownell, Philo H. Age 30. Residence Indiantown, Tama County, nativity New York. Enlisted January 5, 1864. Mustered January 5, 1864. Wounded and taken prisoner April 9, 1864, Pleasant Hill Louisiana. - Mustered out November 16, 1864, Davenport Iowa-. (Actually died as a POW 1864)

This was one of the mysteries we hoped your research could shine more light upon.