Before revision: With the de-industrialization of these areas starting in the mid-1960s , cities like Cleveland, Ohio; Detroit, Michigan; Buffalo, New York; Pittsburgh , Pennsylvania; Erie, Pennsylvania; Youngstown, Ohio; Toledo, Ohio; Rochester , New York; and St. Louis , Missouri have experienced a steady decline of the blue-collar workforce and subsequent population decreases .
After revision: With the de-industrialization of these areas beginning in the mid-1960s , cities like Allentown, Bethlehem, Erie, and Pittsburgh in Pennsylvania; Cleveland, Toledo , New York; and St. Louis in Missouri experienced a steady decline of their blue-collar workforce ,and accelerating throughout the late 20th centuryand Youngstown in Ohio; Detroit in Michigan; Buffalo and Rochester in subsequent population decreases .