Norris Winslow was born on May 19, 1835 in Watertown, New York as the son of John Winslow and Betsey Collins Winslow. He attended public schools in Fields Settlement, New York. He also studied at Falley Seminary and Watertown High School. He graduated in 1854, and he became a clerk in a department store owned by Truman Keeler in Watertown, and he was paid $2 a week. After about two years, he bought the stores stock, and became a merchant. 