Despite the competition for jobs, many Irish immigrants supported and became leaders of union efforts, perhaps because they so well understood the power of organizing to meet needs. For instance, Mary Harris, later known as Mother Jones, committed more than fifty years of her life to unionizing workers in various occupations throughout the country. Her dedicated effort resulted in arrests, personal attacks, and many hardships but she also earned audiences with United States presidents from McKinley to Coolidge.

New Deal appointments a decade later enabled Irish politicians to gain the national spotlight through judgeships and other federal positions. These appointments served as precursors to the future success of Irish-American elected leaders such as Chicago Mayor Richard Daley and President John F. Kennedy.