Ives worked as a bank clerk for Guaranty Trust Company in New York City from 1920 to 1923, earning $25 per week. In 1920, he married Elizabeth Minette Skinner, to whom he remained married until her death in 1947; the couple had one son, George. Joining Manufacturers Trust Company in 1923, he was placed in charge of the bank's business activity in Upstate New York and subsequently moved to Norwich. He remained with Manufacturers Trust until 1930, when he entered the general insurance business in Norwich. On February 18, 1930, Ives was elected to the New York State Assembly to fill the vacancy caused by the resignation of Bert Lord. He was reelected many times and remained in the Assembly until 1946, sitting in the 153rd, 154th, 155th, 156th, 157th, 158th, 159th, 160th, 161st, 162nd, 163rd, 164th and 165th New York State Legislatures. Ives was Minority Leader in 1935 and Speaker in 1936. His reelection as Speaker was opposed by his fellow liberal Republicans, who disagreed with his opposition to Governor Herbert H. Lehman's proposed social welfare program. Ives stepped aside in favor of Oswald D. Heck, who subsequently named Ives Majority Leader. He served in that position from 1937 to 1946. From 1938 to 1946, Ives was chairman of the State Joint Legislative Committee on Industrial and Labor Conditions. In that position he earned nationwide attention for sponsoring the Ives-Quinn Act of 1945, the first state law to prohibit discrimination in employment on the basis of race, creed, color, or national origin. Ives also introduced legislation to create the state Department of Commerce and to establish the New York State School of Industrial and Labor Relations at Cornell University, of which he was dean from 1945 to 1947. He also served as a member of the New York State War Council, chairman of New York State Temporary Commission Against Discrimination, and chairman of the New York State Temporary Commission on Agriculture.
U.S. Senate
In 1946, when Democratic incumbent James M. Mead decided to run for Governor of New York, Ives successfully ran for Mead's seat in the United States Senate. He faced former Governor Lehman in the general election, during which he became the first Republican to be endorsed by the New York American Federation of Labor. He defeated Lehman by a margin of 52% to 47%. Ives was the first Republican to represent New York in the Senate since James W. Wadsworth, Jr., who was defeated for reelection in 1926. Despite his moderate reputation, Ives supported the Taft–Hartley Act in 1947 and voted to override President Harry S. Truman's veto of it; he subsequently lost his longstanding support from labor unions. He served as a delegate to the 1948 Republican National Convention in Philadelphia, Pennsylvania, which nominated his friend and fellow liberal New Yorker Thomas E. Dewey. That same year he married his longtime secretary, Marion Mead Crain. Ives was elected to a second term in 1952, defeating Brooklyn borough presidentJohn Cashmore by 55% to 36%. He received the largest number of votes hitherto ever won by a candidate in New York, carrying all but three of the state's 62 counties. A strong supporter of General Dwight D. Eisenhower, he served as a delegate to the 1952 Republican National Convention in Chicago, Illinois. In 1954, Ives unsuccessfully ran to succeed Dewey as governor of New York. In one of the closest gubernatorial elections in state history, he lost to Democrat W. Averell Harriman by 11,125 votes. Ives was a delegate to the 1956 Republican National Convention in San Francisco, California. In 1958, he co-sponsored a bill with Senator John F. Kennedy to correct abuses within organized labor as disclosed in hearings before the Rackets Committee.