World War I

image icon - click to for more details about the image African American soldiers in the Argonne Forest; Woman’s contribution on the home front; Jumping a trench; British Mark 1 tank; Dropping bombs; Burgess Seaplane; The Great White Fleet; Biplanes in formation

By the
of the 20th Century, industrial innovation and the growth of mass assembly plants, coupled with an influx of millions of immigrant workers, had transformed the United States into a manufacturing powerhouse.

That might was on display in 1907, when President Theodore Roosevelt directed the U.S. Navy to circumnavigate the world with a “Great White Fleet” of sixteen battleships. The fourteen-month journey made nautical history as the first fleet of steam-powered, steel warships to traverse the globe, and successfully projected the United States as a naval and industrial power. Six years later, the Ford Motor Company began operating its first assembly line, enabling the production of a Model T automobile in a fraction of the previous time. It revolutionized how heavy machinery was manufactured, accelerating production while reducing required manpower.

The Outbreak of War

In 1914, the outbreak of war in Europe required the production of arms and munitions on an unprecedented scale. Though the United States was not a participant, military planners in Berlin were aware of America’s manufacturing prowess, and wary of the advantage such production could provide to Germany’s adversaries. That became the case as, early in the war, the United States began selling thousands of tons of desperately needed explosives and munitions to what was known as the Triple Entente or the Allied Powers (Great Britain, France, and Russia). Though the United States was technically neutral in the war, British naval dominance in the Atlantic Ocean forced American munitions manufacturers’ hands. If they sent munitions to Germany, they would be sunk.

In response, German intelligence operatives took aim at a thriving but vulnerable U.S. manufacturing sector, determined to stem the flow of such material to Great Britain, France, and Russia. They achieved considerable success.

Sabotage on the Home Front

At first, many of these early acts of German sabotage were wrongly attributed to industrial accidents or found to have unknown causes. As with the Revolutionary War and Civil War, the United States lacked a centralized intelligence organization when hostilities in Europe began. Nor did existing federal law enforcement agencies have sufficient authorities or capabilities to investigate subversive activities on American soil. Army and Navy intelligence, both created in the 1880s, were also woefully underfunded and understaffed and failed to alert law enforcement agencies to the German threat.

The Evolution of Espionage

Beyond industrialization and foreign sabotage, World War I, “the Great War,” as it would be called, introduced other elements of modern warfare, including sophisticated weaponry, military aviation, and advances in communications technology. The latter allowed intelligence operators on both sides to intercept wire transmissions, break sophisticated codes, and expose the senders’ plans and intentions. Amid the rise of modern signals intelligence, the British achieved a seminal codebreaking coup in 1917, discovering an elaborate German plot targeting the United States. After three years of stalemate in the trenches of France and Belgium, the revelation became a tipping point, drawing America into the conflict and fundamentally changing the tide of the war.

image icon - click to for more details about the image Crossing "no man’s land"