Figuring out what counties were where at a given point in time, and correlating that with the records is necessary, because a family may not have moved, but the county of record did change. The unlined counties show the counties that formed MERCER COUNTY. Montgomery County was formed in 1777 from a part of Fincastle County. It encompassed land that later become Wyoming, Raleigh, Fayette, McDowell, Summers and Mercer Counties in West Virginia as well as Tazewell, Bland, Giles, Smyth, Wythe, Grayson Carroll, Pulaski, Craig, Floyd, and part of Roanoke and Montgomery Counties in Virginia. Starting one year after it was formed, Montgomery County became a parent for five new counties over the next fifty three years. First was Greenbrier County, formed in 1778 from Montgomery, Botetourt and Augusta Counties. Greenbrier County and Montgomery Counties formed what would be southern half of West Virginia. Then Kanawha County was formed in 1789 from Greenbrier and Montgomery. Next, Wythe County was formed in 1790 from Montgomery County and Tazewell County was formed in 1800 from Wythe County. Giles County was formed in 1806 from Montgomery, Monroe (formed in 1799 from Greenbrier County) and Tazewell Counties. The fifth was Floyd County formed in 1831 from Montgomery. Although MERCER County was formed in 1837 from Giles & Taxewell County, the marriage records available in the Mercer County Court House starts at 1854. The earlier marriage records have been lost.