She was active in Republican politics, supported the Equal Rights Amendment, and later turned to writing and philanthropy to help her causes.

[1][2] Her father was a stockbroker who went broke during the Great Depression, and her mother worked in a dress shop to support the household.

[5][6] Ridder dedicated her life to fighting for women's access to opportunities in education and athletics, that she did not have as a young lady who grew up before Title IX came into effect.

[4][5][6] She also sat on the board of trustees for the William Mitchell College of Law,[3] and the accreditation committee for the American Bar Association.

[5][6] The University of Minnesota also awards the "Kathleen C. and Robert B. Ridder Scholarship" annually to a student athlete on the Golden Gophers women's ice hockey team.