A native of Pike County, in western Illinois, Rep. O’Neill married in 1904 and moved to the Chicago area to pursue a career. She was inspired to enter politics by U.S. Rep. Jeanette Rankin (R-Montana), who became the first woman elected to the U.S. Congress in 1916. She became active in the Business and Professional Women, and before long she was an activist for equal voting rights, working with the League of Women Voters during the debate on the 19th Amendment. Illinois gradually granted women the right to vote – starting in 1913 with legislation allowing women to vote only for President, but O’Neill would not be satisfied until women had access to the entire ballot.