This Day in History — American History

On May 18, 1917, General John J. Pershing and the first units of the American Expeditionary Force were ordered to France, marking America’s direct entry into World War I. The deployment strengthened Allied morale, expanded U.S. influence abroad, and helped shape the outcome of the war and America’s future global role.

In 1804, Meriwether Lewis and William Clark launched their historic expedition from St. Louis under President Thomas Jefferson’s orders. Tasked with exploring the Louisiana Territory and finding a route to the Pacific, the Corps of Discovery mapped unknown lands, documented wildlife, and forged relationships with Native American tribes across the frontier.

On May 13, 1846, Congress approved President James K. Polk’s request to declare war on Mexico after escalating border disputes along the Rio Grande. The conflict, driven by Manifest Destiny and territorial ambitions, reshaped North America, expanded U.S. territory westward, and intensified national debates over slavery and American expansion.

Benjamin Franklin’s “Join, or Die” cartoon, published on May 9, 1754, became the first political cartoon in an American newspaper. Created during the French and Indian War, the segmented snake symbolized the need for colonial unity and later evolved into a powerful emblem of resistance during the American Revolution.

Created by President Franklin D. Roosevelt on May 6, 1935, the Works Progress Administration became a cornerstone of the New Deal during the Great Depression. The WPA employed millions of Americans in public works, infrastructure, and cultural projects, helping restore economic stability, national morale, and hope during one of America’s hardest eras.