Located in the geographic center of Maryland, Baltimore County almost completely surrounds the city of Baltimore, which was divided as an independent city in 1851. The county is the largest jurisdiction in the metropolitan area, with a population of more than 800,000 inhabitants. Baltimore County is a hub of highways that connect from north to south and from east to west that provide excellent and efficient access to any area. All land classified as industrial zones in the county is within five miles (eight kilometers) of an interstate highway. Well-maintained state and county highways, which cover more than 2,750 miles (4,300 kilometers), serve areas not reached by the extensive highway system.
The county maintains more than 2,224 miles (3,759 kilometers) of these roads. A portion of northeastern Baltimore County, as well as a portion of northwestern Kent County, was divided to create Cecil County. A new courthouse in Simm's Choice, on the Baltimore County side of Little Gunpowder Falls, had apparently been under construction since 1692. In 1816, the City of Baltimore annexed from Baltimore County several plots of land known as the Precincts on the west, north, east and southwest sides. Much of Baltimore County is suburban and extends on both sides of the border between the Piedmont Plateau to the northwest and into the southern and southeastern regions of the county bordering the Patapsco River and the Chesapeake Bay, the Atlantic coastal plain.
The site of the courthouse, jail, and seat of Baltimore County was evidently Old Baltimore, near the Bush River, on land that in 1773 became part of Harford County. Previously, the (former) Baltimore County was known more as a geographical entity than a political entity, and its territorial boundaries included most of northeastern Maryland, which was then the province's northwestern border and included the current jurisdictions of the city of Baltimore, Cecil and Harford Counties, and parts of Carroll, Anne Arundel, Frederick, Howard and Kent Counties. Northern Baltimore County is mainly rural, with a landscape of rolling hills and deciduous forests characteristic of mixed forests in the southeast, and it shares geography with its neighbors in the east and west, Carroll and Harford Counties, and goes north across the historic Mason-Dixon line to Adams and York Counties, in south-central Pennsylvania. The Maryland Transit Administration (MTA) operates three rail systems: a light rail, rapid transit and a commuter rail in the Baltimore area; all three systems have stations in Baltimore County. The modern Baltimore County Sheriff's Department is responsible for the security of the county's two main circuit court buildings and several courtrooms elsewhere, as well as for the processing and service of court orders. In 1674, a landlord's proclamation established the then-extensive boundary lines of old Baltimore County.
Established in the mid-17th century, the position of Baltimore County Sheriff was initially appointed by county judges between 1662 and 1676. The name Baltimore derives from Cecil Calvert, second Baron of Baltimore (1605-1667), owner of the new colony in the province of Maryland and of the city of Baltimore in County Cork (Ireland). The old rail lines that crossed the county in the early 19th century were the Maryland and Pennsylvania Railroad (MPR) and the Northern Central Railway (formerly the Baltimore and Susquehanna Railroad, which later became part of the old Pennsylvania Railroad). The Fire Department provides fire protection, emergency medical services, and emergency rescue services to the county and surrounding areas, including the city of Baltimore, through mutual aid pacts with those jurisdictions. The Baltimore County Executive oversees the executive branch of county government which is responsible for implementing county law and overseeing government operations.
Baltimore County is home to a diversified economy with special emphasis on education, government and health care.