Garland was a volunteer in the Washington Battalion of the XV International Brigade fighting for Republican Spain during the Spanish Civil War.

He was employed by NBC as an arranger and was attached to the media department producing Your Hit Parade (sponsored by Lucky Strike Cigarettes.)

[2] The outbreak of the Spanish Civil War in 1936 resulted in many international communist parties sending manpower and financial support to Republican Spain.

Once in Spain he joined what would become the Abraham Lincoln Battalion, in which he was appointed section commander on account of his previous military experience.

In August he collaborated with Langston Hughes and Harry Haywood to broadcast a radio message to the United States live from Spain with the intent to drum up support for the Republican cause.

Garland continued to be active with the Friends of the Abraham Lincoln Brigade and the American Medical Bureau after the defeat of the Republican cause in 1939.

Following the entry of the United States into World War II, Garland attempted to reenlist in the US Army but was initially denied.