||Origin: The legal origin of Baltimore County is not known, but it was in existence by January 12, 1659/60 when a writ was issued to the sheriff of the county. The County name was derived from the name of the Proprietary's Barony in Ireland in the county of Longford.
County Seat: Towson, MD 21204
Form of Government: Charter since 1956
1990 census: 692,134
2000 census: 754,292