Ellickson started her career in the workers' education movement, teaching and writing for Brookwood Labor College (1929-1932), the Bryn Mawr Summer School for Women Workers in Industry (1927-1949), and the Federal Emergency Relief Administration (FERA) Southern teachers' training school in 1934.
In the late 1930s she worked for the fledgling Congress of Industrial Organizations (CIO) as assistant to director John Brophy at the national office, doing organizational work, research, and speechwriting [REF].