 Following 15 years of investment at O'Hare Airport and Midway Airport in the early 1970s, the north urban airport became a strain for the north central suburbs of Cook County in the mid 1980s.State legislators from north suburban Cook and DuPage counties applied political pressure to control expansion of O'Hare.House and Senate legislators tried three times to pass a Metropolitan Airport Authority bill from 1985 to 1987, in an effort to alleviate airspace noise and pollution from the urban airport.