He was born in Connecticut. Mitchell worked as a teacher before turning to publishing geography textbooks and maps. He became involved in geography after teaching and realizing that there were so many poor quality geographical resources available to teachers. He moved to Philadelphia, Pennsylvania in either 1829 or 1830. He was in Philadelphia when he founded his company. His son, S. Augustus Mitchell, became owner in 1860. Their publications covered all genres of geography: maps, travel guides, textbooks, and more. Sales of his 24 works reached an annual volume of over 400,000 copies.