Her father, Andrew Richards (c. 1846–1916), was the son of slaveowners, but had come to hate the institution, enlisting as a bugler and drummer boy in the Union Army at the outbreak of the American Civil War in 1861.
[1] Following the conclusion of the war he had married his childhood sweetheart and moved to the western Kansas frontier, where he and his wife Lucy brought up Kate and her four siblings, raising the children as socialists from an early age.
In 1901, she moved to Girard, Kansas to attend the International School of Social Economy where she met her future husband Frank P. O'Hare.
In the pages of the National Rip-Saw, a St. Louis-based socialist journal in the 1910s, O'Hare championed reforms in favor of the working class and toured the country as an orator.
With support of the fledgling ACLU, the women and children stood at the gates of the White House for almost two months before Harding met with them, ultimately releasing many of the prisoners of conscience.
O'Hare worked on behalf of Upton Sinclair's radical populist campaign in the 1934 California gubernatorial election, and briefly served on the staff of Wisconsin Progressive Party politician Thomas R. Amlie in 1937–38.