Columbia is a census-designated place in Howard County, Maryland, United States. It is a planned community consisting of 10 self-contained villages. The census-designated place had a population of 104,681 at the 2020 census, making it the second most populous community in Maryland after Baltimore. Columbia, located between Baltimore and Washington, D.C., is officially part of the Baltimore metropolitan area. Columbia proper consists only of that territory governed by the Columbia Association, but larger areas are included under its name by the U.S. Postal Service and the Census Bureau. These include several other communities which predate Columbia, including Simpsonville, Atholton, and in the case of the census, part of Clarksville. Columbia began with the idea that a city could enhance its residents’ quality of life. Developer James Rouse attempted to create the new community in terms of human values, rather than economics and engineering. Opened in 1967, Columbia was intended to not only eliminate the inconveniences of then-current subdivision design, but also eliminate racial, religious and class segregation.