From Michigan Place Names
Shiawassee County: Obed Hathaway bought the first land here in 1836 and he and his family became the first settlers in 1837. John and William Palmer came in 1838 and named the town after their native Middlebury, N.Y. (which their father had named after his native Middlebury, Vt.). George W. Slocum became the first postmaster of Middleburgh (there was another Middlebury post office in Michigan then) on July 13, 1848, the office operating until Sept. 25, 1862 [Ellis; PO Archives]