 In 1959 the 246th Coast Artillery became the 246th Field Artillery, with its 1st and 2d Battalions forming part of the 29th Infantry Division.National Guard units can be mobilized at any time by presidential order to supplement regular armed forces, and upon declaration of a state of emergency by the governor of the state in which they serve.Unlike Army Reserve members, National Guard members cannot be mobilized individually (except through voluntary transfers and Temporary Duty Assignments TDY), but only as part of their respective units.