Hey there
the answer to ur question is
On the outbreak of the Spanish Civil War President Franklin D. Roosevelt declared the United Statesgovernment would remain neutral in the conflict. The United States government also took measures to restrict its citizens from selling arms to the Nationalists and Republicans.
However some Americans did take part in the fighting. The Abraham Lincoln Battalion was established by those wanting to fight for the Republic during the war. The first volunteers sailed from New York Cityon 25th December, 1936 and joined the other International Brigades at Albacete
hopes this helps u