Stephen Benedict Grummond was born on September 18, 1834, in
Marine City, Michigan, the son of Stephen Benedict and Mary Harrow Grummond. The elder Grummond was a successful businessman who ran a general store in Marine City. Starting at age 15, the younger Grummond served on merchant ships in the summer and continued his schooling during the winter months. Using his savings and some investment from his father, Grummond purchased a merchant vessel of his own and sailed her for several years. In 1855, he sold his first vessel, moved to Detroit, and purchased another; Grummond continued in the business of buying, selling, and operating various vessels. He established Grummond's Mackinac Line of steamers, and at one time owned the largest tug and wrecking business on the
Great Lakes. He built up a great fortune, much of it in the tugging business, and expanded into barges, lumber, and Detroit real estate. ==Politics and personal life==