Kate Crane Gartz was born Katherine Elizabeth Crane in 1865 to the wealthy Crane family, who made their fortune in ironworks.
Crane Gartz grew up in Chicago, where she became familiar with Jane Addams' Hull House, to which her father donated money.
Early exposure to the contrast of her own affluence with the poverty of those in Chicago's tenement district led Crane Gartz
to dedicate much of her life to philanthropy and communism. She moved to Altadena, California, in 1907, where she lived until
her death in 1949. Crane Gartz hosted weekly salons for leftist and intellectual discussions in her Altadena home, The Cloisters.
She wrote extensively and published several books.