New York metropolitan area eight subregions are often further divided. For instance, Long Island can be divided into its South and North Shores (usually when speaking about Nassau County and western Suffolk County) and the East End. The Hudson Valley and Connecticut are sometimes grouped together and referred to as the Northern Suburbs, largely because of the shared usage of the Metro-North Railroad system. The geographical, cultural, and economic center of the metropolitan area is New York City, which consists of five boroughs, each of which is also a county of New York State. The five boroughs – Brooklyn, Queens, Manhattan, the Bronx, and
Manhattan of Greater New York", Manhattan and the Bronx, though still one county, were established as two separate boroughs. On January 1, 1914, the New York State Legislature created Bronx County, and New York County was reduced to its present boundaries. The construction of the New York City Subway, which opened in 1904, helped bind the new city together, as did additional bridges to Brooklyn. In the 1920s Manhattan experienced large arrivals of African-Americans as part of the Great Migration from the southern United States, and the Harlem Renaissance, part of a larger boom time in the Prohibition era that included