With the help from Clayton Van Lydegraf, the Weather Underground sought a more Marxist–Leninist ideological approach to the post-Vietnam reality. The leading members of the Weather Underground (Bill Ayers, Bernardine Dohrn, Jeff Jones, and Celia Sojourn) collaborated on ideas and published a manifesto: "Prairie Fire: The Politics of Revolutionary Anti-Imperialism." The name came from a quote by Mao Zedong, "a single spark can set a prairie fire." By the summer of 1974, five thousand copies had surfaced in coffee houses, bookstores and public libraries across the U.S. Leftist newspapers praised the manifesto.