Socialist Unity was a Trotskyist group in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It was founded by former members of the Socialist Workers Party

Socialist Workers Party (United States)

The Socialist Workers Party is a far-left political organization in the United States. The group places a priority on "solidarity work" to aid strikes and is strongly supportive of Cuba...

 (SWP) in 1985, around Les Evans who wanted to maintain links with the United Secretariat of the Fourth International. Immediately after being expelled from the SWP, future Socialist Unity supporters formed part of the Socialist Action

Socialist Action

Socialist Action may refer to:*Socialist Action , a Trotskyist political party in the United States*Socialist Action , a Trotskyist group in the United Kingdom that published a magazine of the same name until 2001...

 but left that grouping in favour of joining the Solidarity

Solidarity (US)

In left-wing politics in the United States, Solidarity is a socialist organization associated with the journal Against the Current. Solidarity is an organizational descendant of International Socialists, a Trotskyist organization based on the proposition that the Soviet Union was not a "degenerate...

 with the International Socialists

International Socialists (US)

The International Socialists was a Third Camp Trotskyist group in the United States.The roots of the IS went back to the fall of 1964 when the Berkeley locals of the SP-SDF and YPSL left with 16 members to found the Independent Socialist Club led by Hal Draper and Joel Geier...

 and Workers Power

Workers Power (US)

Workers Power was a short lived Trotskyist faction in the late 1970s and early 1980s.In the 1970s the Third Camp group International Socialists carried out its most successful work within organized labor within the International Brotherhood of Teamsters, helping to organize rank-and-file opposition...

 in 1986. Within Solidarity they constituted a Fourth International Caucus

Fourth International Caucus

The Fourth International Caucus is a grouping of members of Solidarity in the USA who support the Fourth International. It originated from a group who was expelled by the Socialist Workers Party in 1985. Some of them formed the group Socialist Action, from which in turn came Socialist Unity...

which retains links with the United Secretariat of the Fourth International in this capacity.