Final answer:
The United States, along with British and Canadian forces, led the D-Day invasion of northern France on June 6, 1944, as part of Operation Overlord.
Step-by-step explanation:
On D-Day, forces led by the United States, along with British and Canadian allies, invaded northern France. The operation, known as Operation Overlord, commenced on June 6, 1944, and was the largest amphibious assault in history. Under the direction of General Eisenhower, the Supreme Allied Commander in Europe, more than 150,000 troops landed on the Normandy beaches famous for codenames Sword, Juno, Gold, Omaha, and Utah. Supported by a formidable fleet of ships, aircraft, and vehicles, the Allied forces caught the German defenders off guard, partly due to deceptive measures suggesting the invasion might occur near Calais.
Following intense conflict, the Allies secured a beachhead, enabling them to bring additional troops and heavy equipment ashore, leading to the eventual liberation of Paris and pushing forward across western Europe.