The United States was at war! We officially entered World War I on April 6, 1917. Less than a month later, on May 2, Major General John J. Pershing was notified that he was under consideration to command expeditionary forces sent to the main fighting front in France. Originally projected as just four regiments, his American Expeditionary Force would grow to encompass 43 divisions, grouped into nine corps, and three field armies. All of those divisions were created during the war.

With Americans today accustomed to a large standing military, it is hard to believe that on the eve of American entry into World War I, the United States Army was still operating under the mid-nineteenth century concept of organization. The storied divisions, imprinted forever in the pages of the American military history, had yet to come into being. The names of units that would later become household words in the twentieth century were still unknown - - the Big Red One, 1st Division; the All-American, 82nd Division; or the Rainbow Division, 42nd Division were all in the future.

The Army was still patterned on the Civil War model, running from the company level and increasing in strength up to Army level. During this period immediately prior to World War I, the company still functioned as the basic building block for all organizations; little attention was given to any organization below the company. A company had just over 100 soldiers assigned with a captain in command; twelve companies formed the regiment under a colonel; generally, three to five regiments formed the brigade, commanded by a more senior colonel or in some cases a Brigadier General. Three to five brigades comprised a division, commanded by a Major General and three to five divisions produced a corps. Above the corps level, the pattern changed with no set number of corps forming an Army.

Following the War with Spain in 1898, the Army drew heavy criticism because of its inflexible structure and lackluster execution of mobilization. As a result, then Secretary of War Elihu Root directed a series of studies designed to transform the organization of the Army.

By 1917, that new organization emerged as a transformed Army on the Twentieth Century model, centering around fighting divisions and corps. Those divisions came from all three components of the modern Army: the Regular Army, which incorporated the active duty regiments of the Army; the National Guard, composed of the state regiments and the divisions formed for emergency service on the Mexican Border; and a new arm, the National Army, or Reserves, created to accommodate conscripts drafted under resultant of the Selective Service Act.

This was the modern Army which General Pershing led in an unprecedented deployment of American Forces to Europe, 1917-1918. Their ensuing combat service in France under his leadership earned those divisions enduring renown. Their numbers, their nicknames, their fame -- enriched by succeeding generations of Soldiers in subsequent wars -- have come down to our own time. The structure of fighting divisions and corps from the First World War remains with us today.

In addition to great changes in structure, this period also witnessed the birth of the divisional shoulder sleeve insignia so readily recognizable at present. Insignia used to distinguish soldiers on the battlefield was not new in the American tradition. Historians generally acknowledge that Major General Joseph Hooker established a system of divisional and corps insignia during his tenure as commander of the Army of the Potomac, during the Civil War. These insignia quickly became a treasured part of unit identity adding to the organizational esprit de corps.

With the establishment of a large American Army, it was only natural that unit level insignia would appear in the American Expeditionary Force. By some accounts, it was the 81st Division that started the trend when they arrived at the Port of Embarkation with the "Wildcat" patch on their shoulder. Whoever was responsible, by the end of the war, shoulder sleeve insignia was universal with hundreds of separate and distinct designs creating the basis for our contemporary unit insignia.

Although the great trials in combat of both World War I and World War II remained in the future in 1917, the creation of the American Expeditionary Force reshaped an outmoded force, bringing it forward into the new century and laying the foundation for our Army today.