A Democrat, in 1964 he was elected to the U.S. House from the 2nd District after incumbent Republican Clifford McIntire ran unsuccessfully for the United States Senate, and he served from 1965 until 1973.In 1972 Hathaway ran for the United States Senate and defeated four-term Republican incumbent Margaret Chase Smith in a considerable upset.Hathaway was an unsuccessful candidate for reelection in 1978, losing to his successor in the 2nd District, future Secretary of Defense William Cohen, by 22 percentage points.In June 2002, at the age of 78, Hathaway was awarded the Distinguished Flying Cross for heroism during Operation Tidal Wave.[6] Hathaway was married to Mary Lee Bird of Horse Shoe, North Carolina, and Akron, Ohio, for over 61 years until her death, in 2007.