That the Soviets – and now Russia – seek to leverage US domestic issues such as racism to their advantage is unsurprising, but this little vignette is interesting, not least because of the year, 1926, two decades before the Cold War was so much as a twinkle in anyone's eye.
A cover letter and supporting documentation submitted by the Profintern (Red International of Trade Unions) to the Presidium of the Executive Committee of the Communist International (COMINTERN), and the COMINTERN's response.
The documents were acquired by J.C.White and team. White was Chargé d'Affaires, Legation of the United States, Riga, Latvia. This was a period of Latvian independence between the wars. This period also predates the creation of the CIA by about 20 years, and so the State Department bore the burden.
Stamps on the coversheet trace the documents as they moved from Riga, to the Division of Eastern European Affairs, to an Under Secretary at Department of State, at which point a hand-written note "To Justice 6-16-26" indicates State was sharing intel with DOJ, and other documents from the same collection and time period make it clear that sharing with DOJ meant J.Edgar Hoover and his Bureau of Investigation (J.Edgar became Dir FBI in 1924).
While it is unclear how the United States came to possess the documents, monitoring activities of Communists was clearly among the tasks performed by the US Legation in Riga. See, for example, this report on the 1st World Congress of the Profintern, dated July 28, 1921.
The documents are among the few bits of the Natalie Grant Wraga papers held by the Hoover Institution at Stanford University that are available online: J. C. White letter forwarding materials on the problem of the Negro movement in North America, with attachments. How or why they turned up in Wraga's papers is unknown (aside from the obvious, that they passed through her hands and she kept a copy).
The Soviets – for ideological reasons, and in contrast to their Russian successors – were more interested in bringing people together than tearing them apart (at least as far as the working class was concerned). This was their problem. They sought to unify, radicalize, and grow the US labor movement.
From their perspective, integrating African American workers into US unions made perfect sense. What is clear from the report to the COMINTERN, however, is that white American trade unionists were not generally interested in allowing blacks into the unions (with a few exceptions, e.g. the garment workers and longshoremen).
While the Communists were committed to trying to integrate American unions, they determined that they could get farther more quickly if they separately sought to aid and guide African American trade unions that arose in industries where white organized labor was adamant about keeping blacks out.
That, of course, would require (more) money from Moscow. The COMINTERN was broke and wanted the US Communist Party to dedicate funds already provided to them, while the US Communist Party claimed they had no money to spare. In the meantime, it was agreed that someone would be appointed to work with the black unions.
A copy of the documents discuss will be found here, though I recommend perusing the collection at the Hoover Institution.