The Washington Post recently published a map depicting 15 different types of counties across America. As described in the Post,
The map was developed by The American Community Project, along with WNYC, which categorized each of our nation’s 3,144 counties into one of fifteen types— such as “Big Cities,” “Urban Suburbs,” “College Towns,” and so forth. . . “Counties” are funny things. They vary enormously in land area, population, culture, and so forth, and unlike states they often have no particular political significance. But if nothing else they make a very fun unit for data visualization.
In Maryland, however, counties have significant political importance. As the Maryland Department of Legislative Services describes in Maryland Local Government,
Counties are the principal unit of local government in Maryland, responsible for most basic services, such as police, fire, local corrections, sanitation, highways, health, and parks and recreation. In addition, counties in Maryland are responsible for funding public schools, libraries, local community colleges, and the circuit courts. This arrangement is similar to other state south of the Mason-Dixon Line. Northern states traditionally rely more on townships to provide local services.
Maryland’s 23 counties and Baltimore City are typed by the American Community Project as the following:
Military Posts 
Graying America
Working Class Country 
Rural Middle America
Middle Suburbs 
Exurbs
African American South 
College Towns
Urban Suburbs 
Big Cities
To see how your county is depicted, along with other counties across the nation, see the Washington Post.
