John was born on a farm near Sugar Grove, IN. He and his brother, William, entered DePauw University, then known as Indiana Asbury, where both joined Sigma Chi. An outstanding lawyer and a successful businessman, McMillin was the founder of Roche Harbor, located on San Juan Island, president and general manager of the Roche Harbor Lime and Cement Company, and owner of the Hotel de Haro.
The John S. McMillin Memorial Monument is listed on the National Register of Historic Places, U.S. Department of the Interior. The limestone table in the center of the mausoleum represented the McMillin family table, around which all the family would symbolically gather in the hereafter. There is a chair for each of the six family members. He incorporated into his family mausoleum many Masonic, family, and fraternity symbols.
"John Stafford McMillin, A.B., A.M., LL.D. A 32° Mason - Knight Templar - Noble of Mystic Shrine Sigma Chi - Methodist - Republican"