The defining role of the National Guard in WWI

On August 5, 1917, the entire United States National Guard was taken into national service, subject to presidential rather than state control. An excerpt from the article:

"Over 100 years ago, on August 5, 1917, the entire National Guard was drafted into U.S. Army service for World War I. This represented the culmination of several steps declared by President Woodrow Wilson that would mobilize the National Guard into the "Great War" and which sent troops into Europe for the first time.

This act stands among a series of laws and military decisions in the early 20th century that resulted in the transformation of the National Guard from a traditionally local military organization into professional military force. A little over a year earlier, the National Defense Act of 1916 introduced the modern integration of National Guard Soldiers as an element of the United States Army. It required that Guard members in federal service would serve in the U.S. Army uniform and train to federal standards, in addition to other measures designed to improve readiness and efficiency.

However, the 1916 Act did not authorize the transportation of federalized National Guard troops to a foreign country. The Judge Advocate General of the U.S. Army ruled that the Guard could only be used domestically, owing to the Militia Clause of the U.S. Constitution that only allowed the National Guard in federal status to "execute the laws of the union, suppress insurrection and repel invasions." This phrase alone deemed necessary the draft action.

The mobilization order of June 18, 1916, that ordered the Guard to the Mexican border represented the second milestone among the changes in national defense strategy. It demonstrated the power of the National Guard as the country's principal reserve force for the U.S. Army to be mobilized in a declared national emergency. This gradual evolution of legal precedents allowed the Army ample opportunity to make corrective action and improve the deployment process. Heightened national security concerns earlier in 1917 allowed the National Guard's mobilization to move forward after the draft order of August 5.

The draft's impact was immediate. On June 30, 1917, the Regular Army consisted of 250,357 officers and enlisted men. By August 5, 1917, through means of incremental federalization of state National Guards and the draft order, 379,323 officers and enlisted men of the National Guard were drafted into the federal service."