After splitting with Trotsky over the latter's support for the Soviet Union in the Russo-Finnish War, Shachtman formed the Workers Party. In 1948, the Party was renamed the Independent Socialist League (ISL).
In 1953, Shachtman helped Michael Harrington instigate the Young People's Socialist League (YPSL)'s split with its parent organisation, the Socialist Party. The following year, the YPSL merged with the ISL's Socialist Youth League to form the Young Socialist League.
In 1958, the ISL successfully challenged its inclusion on the US Attorney-General's Subversive List.
- Yetta Barsh Shachtman - wife
- Marxists' internet Archive Max Shachtman
- Ralph Seliger, Max Shachtman: Progenitor of 3rd Camp & Neocons, Tikkun Daily, 25 August 2012.
- Albert Glotzer, MAX SHACHTMAN – A POLITICAL-BIOGRAPHICAL ESSAY, marxists.org, accessed 10 January 2013.
- Maurice Isserman, The Other American: The Life of Michael Harrington, PublicAffairs, 2001, p.124.
- Robert Jackson Alexander, International Trotskyism, 1929-1985: A Documented Analysis of the Movement, Duke University Press, 1991, p.899.