Background
Below, you will find the available records from FBI File 121-HQ-23278, which deals with Alleged Communists in the State Department, which dates back to 1950.
The FOIA case is still ongoing, but the released records are below.
Document Archive
FBI File 121-HQ-23278: Alleged Communists in the State Department – FBI Release #1 – [2,139 Pages, 175MB]