Chamberlain received the United States' highest award for bravery during combat, the Medal of Honor, for his action during the Battle of Chickamauga, Georgia on 20 September 1863.

Married Helen Maria Mead (1843-1911) and they had one child, Edith Chamberlain (1872-1933).

In 1914 served in Washington as acting chairman of Legislation Army and Navy Medal of Honor Legion of U.S.A. and was a proponent of $10 per month pension addition for medal of honor recipients.

[3] He died on May 27, 1929, and his remains are interred at the Grace Lawn Cemetery in Elkhart, Indiana.

While exposed to a galling fire, went in search of another regiment, found its location, procured ammunition from the men thereof, and returned with the ammunition to his own company.