 The National Guard had previously been limited to service within each state, or federal activation within the United States for up to nine months.Under the 1916 Act, members of the National Guard could be discharged from the militia and drafted into the United States Army for overseas service (to comply with a 1912 decision by the Judge Advocate General of the Army that used a constitutional argument to restrict the overseas use of the National Guard), and could be called up for an unlimited duration.In addition, the Army was prevented from recruiting volunteer units to expand the organization in time of war until after the National Guard had been called up.