Wikipedia
The Rust Belt is a term for the region straddling the upper North-Eastern United States, the Great Lakes, and the Midwest States, referring to economic decline, population loss, and urban decay due to the shrinking of its once-powerful industrial sector. The term gained popularity in the U.S. in the 1980s.
The Rust Belt begins in New York and traverses to the west through Pennsylvania, West Virginia, Ohio, Indiana, and the Lower Peninsula of Michigan, ending in northern Illinois and eastern Wisconsin. Previously known as the industrial heartland of America, industry has been declining in the region since the mid-20th century due to a variety of economic factors, such as the transfer of manufacturing further West, increased automation, the decline of the US steel and coal industries, free trade agreements such as the North America Free Trade Agreement (N.A.F.T.A.) or accession to the World Trade Organization, globalisation, and outsourcing of jobs out of the U.S. While some cities and towns have managed to adapt by shifting focus towards services, others have not fared as well, witnessing rising poverty and declining populations.