 He attended the University of Vermont and the Wharton School of the University of Pennsylvania,

He served in the United States Army Air Corps from 1942 to 1946, and attained the rank of Sergeant.McEwen graduated from Albany Law School in 1947, was admitted to the bar and practiced in Ogdensburg.He was elected to the New York State Senate on January 5, 1954, to fill the vacancy caused by the appointment of Paul D. Graves to the New York Supreme Court.