Dear Ms. Krishpinovich,
Thank you for posting your request on History Hub!
The National Archives does not have custody of visa case files after March 1940. Beginning in April 1940, under normal Department of State records management procedures, such files were destroyed after initial administrative use. If you have additional questions pertaining to these files or procedures, please contact the Department of State Records Manager, SA-2; Room 5117; 515 22nd Street, NW; Washington, DC 20522. The web site for visa information is https://travel.state.gov/content/visas/english.html.
If these students were Argentine nationals, their passport would have been issued by the Argentine government. Please contact Argentina’s General Archive of the Nation to inquire about Argentine government records.
If you know which school they studied at or who sponsored their study abroad program, those institutions may have records concerning them.
We hope this is helpful.
Thank you for your reply and links to the alternate resources. I will continue to research locally (try to find the name of the school or program). That will help a lot. Thank you again,