Frederick County, Maryland, was founded in 1748 from portions of Prince George’s and Baltimore counties. Since the 1980s, it has experienced rapid population growth. The county borders Pennsylvania to the north and Virginia to the south.
In 1776, after American independence, Frederick County was divided into three new counties. The western section became Washington County, named after George Washington, while the southern portion became Montgomery County, honoring General Richard Montgomery. The remaining northern section retained the name Frederick County.
In 1837, part of Frederick County was combined with a section of Baltimore County to create Carroll County, which now lies to the east.
Frederick County boasts numerous sites listed on the National Register of Historic Places.