Born in Norway, New York, Millington attended the district schools of Poland, the Fairfield Academy, and Hungerford Collegiate Institute. He entered the employ of the Hungerford National Bank, Adams, New York. Organized and became cashier of the Bank of Poland. He moved to Herkimer, New York, in 1894 and continued in the banking business. He served as delegate to the 1908 Republican National Convention.
Millington was elected as a Republican to the Sixty-first Congress (March 4, 1909 – March 3, 1911). He was an unsuccessful candidate for reelection in 1910 to the Sixty-second Congress. He resumed business activities in Herkimer, New York. He was appointed by President Taft as Assistant Treasurer of the United States in charge of the subtreasury in New York City on May 12, 1911, and served until his death in Herkimer, New York on October 25, 1913. He was interred in Pine Grove Cemetery, Poland, New York.
This article incorporates public domain material from the Biographical Directory of the United States Congress website http://bioguide.congress.gov.