Samuel Augustus Mitchell (March 20, 1792 - December 20, 1868) began his map publishing career in the early 1830s. Mitchell was born in Bristol, Connecticut. He relocated to Philadelphia in 1821. Having worked as a school teacher and a geographical writer, Mitchell was frustrated with the low quality and inaccuracy of school texts of the period. His first maps were an attempt to rectify this problem. In the next 20 years Mitchell would become the most prominent American map publisher of the mid-19th century. Mitchell worked with prominent engravers J. H. Young, H. S. Tanner, and H. N. Burroughs before attaining the full copyright on his maps in 1847. In 1849 Mitchell either partnered with or sold his plates to Thomas, Cowperthwait and Company who continued to publish the Mitchell's Universal Atlas. By about 1856 most of the Mitchell plates and copyrights were acquired by Charles Desilver who continued to publish the maps, many with modified borders and color schemes, until Mitchell's son, Samuel Augustus Mitchell Junior, entered the picture. In 1859, S.A. Mitchell Jr. purchased most of the plates back from Desilver and introduced his own floral motif border. From 1860 on, he published his own editions of the New General Atlas. The younger Mitchell became as prominent as his father, publishing maps and atlases until 1887, when most of the copyrights were again sold and the Mitchell firm closed its doors for the final time. More by this mapmaker...

William Henry Gamble (November 4, 1835/6 - September 16, 1921) was a topographical engineer, map engraver, and publisher active in Philadelphia during the second half of the 19th century and in Washington D.C. during the early 20th century. Gamble was born in Philadelphia. It is unclear where he received his training as an engraver, but most of his work is associated with the firm of William Augustus Mitchell Jr. In 1895, he relocated to Washington D. C. to engrave for the U.S. Geological Survey and remained active with that institution until his death, at 85. His obituary claims that, at the time, he was the oldest active government employee. In the 1860s his offices were at 29 South 6th Street, and by the 1870s, at 814 N. 12th Street. He maintained this address until relocating to Washington D. C. to take work with the Geological Survey. In Washington D.C. he lived at 1329 Gallatin Street. Learn More...