Samuel Augustus Mitchell (1792-1868) was the most prolific American map publisher of the 19th Century. Originally a school teacher, his frustration with the poor quality of educational maps led him to form his own mapmaking business. In 1830, he purchased the plates and rights to Anthony Finley's New American Atlas (1826) and hired J. H. Young, Finley's chief engraver, to improve and update the plates. He acquired the copyright for Henry S. Tanner's New Universal Atlas (1836) in 1845, and extended the life of the copperplates by having the images transferred to lithographic stone for printing. Mitchell was also a pioneer in the use of steel engraving, employing the technique in the early 1830s, almost 20 years before the general switch to steel was approximately 1850. Mitchell retired in 1860, turning the business over to his son Samuel Augustus Mitchell, Jr. The firm prospered until the 1890s.