From Wikipedia
Hadley is an unincorporated community in the northern part of the township at 42°57′16″N 83°24′12″W. William Hart, Abraham Tunison, and Charles L. Cambell settled here in 1835. A post office opened on May 7, 1838, with John Mills, Jr. as the first postmaster. Circa 1907, Franklin Hadley became postmaster and for fifty years some member of the Hadley family held the office. The Hadley post office, with ZIP code 48440, provide P.O. box service to a small area within the township.