The Taft-Hartley Act's non-communist affidavit turned the Cold War inward on the unions: left-led internationals were expelled from the CIO, and their officers prosecuted for allegedly false affidavits — furriers' leader Ben Gold convicted in 1954, Mine-Mill's Maurice Travis and Clinton Jencks pursued through the decade, with Jencks v. United States (1957) finally forcing the government to show defendants their accusers' FBI reports. Harry Bridges was tried four times across two decades in the government's marathon effort to deport the longshore leader.

Deportation swept the foreign-born left of the labor movement — the ILWU Local 37 cannery leaders Chris Mensalvas and Ernesto Mangaoang among the era's defining cases — while Smith Act prosecutions took union communists from Maurice Braverman to the Flint auto militants. The purge broke industrial unionism's radical wing, and its prisoners fill this database's 1950s pages.