Wythe Co was struck off Montgomery Co in 1790 (the map on the upper left). Wythe Co was itself divided in 1793 to form Grayson Co and again in 1800 to form Tazewell (the center map). Giles Co was formed from the northern part of Montgomery Co in 1806, and the country remained thus up to 1830 (the right-hand map).
Mercer County was formed in 1837 from Giles and Tazewell Counties ( the bottom left-hand map). The center map shows the surrounding territory just before 1871, when Summers Co was formed out of Mercer and Monroe Counties (the bottom right-hand map).
Updated March 6, 2001