After Harvard, he worked in the
American Exchange Bank and the Farmers and Mechanics Bank of Buffalo. After graduating from Law School, he studied with the law firm of Lewis, Moot & Lewis, until his admission to the bar in 1894. After being admitted to the bar, he practiced in the office of Sprague, Moot, Sprague & Brownell until 1897. In 1897, he left Sprague, Moot, Sprague & Brownell and went out on his own, establishing his own practice focusing primarily on real estate. As an attorney, he was responsible for all Sidway family interests in Buffalo, including the management of the Sidway building at Main and Goodell Streets.
Military career March 1, 1894, he was commissioned as
second lieutenant in the Seventy-fourth infantry regiment of the
New York National Guard. On December 15, 1898, also his 29th birthday, he was commissioned a captain of the 202nd
New York Volunteer Infantry and set sail for
Cuba as part of the
Spanish–American War. His regiment was the first body of United States troops to enter Cuba where he served throughout the campaign. In 1902, he resigned from the regiment. In 1917, fourteen years after he resigned, he was again commissioned major of the depot battalion of the Seventy-fourth. On December 6, 1917, when the United States entered
World War I, he was promoted to
lieutenant colonel of that regiment and led in organizing the command that took the place of the regular regiment after its departure for a mobilization camp. ==Personal life==