Mackey is the author of thirteen novels and six collections of poetry. She is noted for her historical fiction, particularly for The Year The Horses Came, The Horses At The Gate, and The Fires of Spring, a trilogy set in Neolithic Europe which Mackey based on the research of archaeologist Marija Gimbutas. She is also noted for her lyric poetry which has been praised by Wendell Berry, Jane Hirshfield, Dennis Nurkse, Ron Hansen, Dennis Schmitz, and Marge Piercy for its beauty, precision, originality, and extraordinary range.
Her first novel, Immersion (Shameless Hussy Press, 1972) is set in the rain forests of Costa Rica. It takes as its subjects ecology and feminism, and is believed to be the first feminist novel published by a Second Wave American feminist press. McCarthy’s List is a comic novel set in Indianapolis in the 1950s. The Last Warrior Queen retells the myth of Inanna, the Sumerian goddess of sexual love, fertility, and warfare. A Grand Passion and The Kindness of Strangers are set in Europe and take as their subject three generations of women involved in the arts. Three of Mackey’s novels (The Year The Horses Came, The Horses At The Gate, and The Fires of Spring) comprise her Earthsong Trilogy. Set in Europe in the Neolithic Period, they deal with struggles between matristic earth-centered goddess-worshipping cultures and invading patriarchal nomads. Mackey’s Season of Shadows is set at Harvard in the late 60’s and deals with various political issues such as the Civil Rights Movement and protests against the United States’ involvement in the Vietnam War. In 2003 and 2004, in a departure from her previous styles and themes, Mackey chose to write The Stand-In and Sweet Revenge under the pen name “Kate Clemens.” Both are comic novels set in Los Angeles. Most recently she has written two Civil War novels, The Notorious Mrs. Winston and The Widow’s War, set in Indiana and Kansas respectively.