The battalion was activated on 20 November 1917 at Quantico, Virginia as the 9th Regiment. During December 1917 they were deployed to Guantanamo Bay, Cuba, and attached to the 3rd Provisional Brigade.
On 20 November 1917, the battalion was activated in Quantico, Virginia as the 9th Regiment. During December 1917, they were deployed to Guantanamo Bay, Cuba, and became part of the 3rd Provisional Brigade.