When the first lodge of what would become the Croatian Fraternal Union of America was founded on January 14, 1894, it marked the beginning of a mutual support group and cultural association that would last well into the 21st century.
It would also mark the creation of an organization that would spend much of the 20th century under the gaze of American law enforcement. As the 8/30/1976 FBI telex to the State Department reveals, the FBI and the State Department were monitoring the Croatian Fraternal Union of America for decades, starting according to this record, in 1942. According to other records I saw in the FBI’s IWG files on the Ustashi, the Croatian Fraternal Union of America was investigated as early as 1940. Why would the Croatian Fraternal Union warrant decades of apparently intense FBI and State Department scrutiny?
The answer, which is based off of documents that I have seen but did not copy, is that the Croatian Fraternal Union of America was investigated as part of a broader investigation into organization that had ethnic, religious, cultural, or political ties to the Tripartite Pact powers. After the establishment of the Independent State of Croatia, this meant that Croatians were a suspect group in the United States. From surviving records, it appears that the Ustasha movement was the most intently investigated, but many Croatian groups were examined including the Croatian Peasant Party, the Croatian Catholic Union, and the Croatian Fraternal Union.
Once the war ended, much of this surveillance was stopped. For example, the FBI files on the Croatian Peasant Party and Croatian Catholic Church largely stop in 1945. I suspect, but cannot prove until I receive the documentation, is that the FBI continued monitoring the Croatian Fraternal Union due to allegations that the organization was “Communist” and had ties to the Socialist Federal Republic of Yugoslavia. After the easing of the Red Scare, I suspect that the Croatian Fraternal Union was subjected to continued investigation for three reasons. During the late 1960s, Croatian militants became more strident in their calls for Croatian independence, even taking actions here in the United States. Judging from the FBI files of Croatian organizations that I have received via FOIA submitted on my behalf, the Croatian agitation reach a point that the FBI could no longer ignore in the 1967-1968 time frame and many of the large Croatian oriented groups were investigated. I suspect it then-ongoing relationship with the Socialist Federal Republic of Yugoslavia led to a continued FBI interest in the Croatian Fraternal Union of America. Finally, the Croatian Fraternal Union would come under attack from some of the Croatian organizations actively seeking Yugoslavia’s destruction. Bernard Luketich received death threats that provided to be anything less than idle in the summer of 1977 when he was attacked by men with lead pipes. (2)
However, this is just semi-informed speculation until I receive the documentation
(1) An example of this is Dinko Šuljak's The Communist conspiracy in the Croatian Fraternal Union