Like many American coastal cities, Baltimore has become a service-oriented economy. Baltimore is home to the National Aquarium, the Maryland Science Center, Harborplace shopping center and the Baltimore Orioles. Greater Baltimore is home to several Fortune 1000 companies such as Constellation Energy, Grace Chemicals, Legg Mason, T. Rowe Price, and McCormick & Company. The Johns Hopkins Hospital is also located in Baltimore. The Baltimore Convention Center that opened in 1980 was built as part of a major city redevelopment project in the late 1970’s. Baltimore was once a major harbor center and the area has since been transformed into an area of commerce, business and tourism steeped in American history. The National Aquarium in Baltimore, the Oriole Park at Camden Yards and the M&T Bank Stadium are also all parts of the major redevelopment and transformation of the historic Baltimore harbor. The city of Baltimore itself is divided into nine geographical regions: Northern, Northwestern, Northeastern, Western, Central, Eastern, Southern, South Western and Southeastern. Downtown Baltimore, the citys main commercial area is located in Central Baltimore. Throughout many of these regions are a total of 72 historical districts, traditionally occupied by distinct ethnic groups.