 McEwen remained in the State Senate until 1964, sitting in the 169th, 170th, 171st, 172nd, 173rd and 174th New York State Legislatures.He was elected as a Republican to the 89th, 90th, 91st, 92nd, 93rd, 94th, 95th and 96th United States Congresses, holding office from January 3, 1965, to January 3, 1981.He did not run for reelection in 1980.