A member of the Republican Party, he served as a United States Senator from Vermont from 1959 until his death.

He was previously a member of the United States House of Representatives, serving Vermont's At-large congressional district, from 1951 to 1959.

[5] Though described as shy and reticent, in part because he was self-conscious about the loss of his right thumb in an accident at his family's business, Prouty decided on a career in politics.

[5] He was an unsuccessful candidate for the Republican nomination for Lieutenant Governor of Vermont in 1948, losing to Harold J.

[11] After longtime incumbent Charles Albert Plumley decided not to run in 1950, Prouty announced his candidacy for the United States House of Representatives from Vermont's At-large congressional district.

[16] Issues with which he was identified included federal aid for school construction, federal funding of courses for students with special needs, arts and music education, and senior citizen needs to include health care and expansion of Social Security eligibility.

[25] Prouty died from the effects of gastric cancer at New England Deaconess Hospital in Boston on September 10, 1971.

[28][29] She died in 1960, and in 1962, Prouty married Jennette Herbert Hall (1913–2002), who had been the chief aide to Congressmen Henry J. Latham of New York and Robert E. Cook of Ohio.