Mitchell's World Map' by Mitchell. Samuel Augustus Mitchell (1792-1864) was a teacher early on, who became dissatisfied with the quality of textbooks available. Moving to Philadelphia, an important center of publishing at the time, he issued A New American Atlas with J.H. Young, his principal engraver. An early adopter of steel plate engraving, his company grew to dominate map publishing of the mid 1800’s. Historically, it was an important time for America, as the Civil War came to a close and the work of uniting the country proceeded along with expansion to the West and continued economic growth. Thus, it was a time of great change for cartographers.