Dunham was a member of the firms of Austin Dunham & Company and E N Kellogg & Company and a senior partner in the firm of Austin Dunham's Sons, manufacturers of worsted yarns and hosiery.
Dunham was a member of the firms of Austin Dunham & Company and E N Kellogg & Company for a few years. Later he became a senior partner in the firm of Austin Dunham's Sons, manufacturers of worsted yarns and hosiery.