The invasion of Normandy
In total, the First Army contingent totaled approximately 73,000 men, including 15,600 from the airborne divisions. The amphibious operation was the largest in American military history since Ulysses S. Grant landed at Bruinsburg during the American Civil War.
British and Canadian Zones:
Overall, the Second Army contingent consisted of 83,115 men, 61,715 of them British. The nominally British air and naval support units included a large number of personnel from Allied nations, including several RAF squadrons manned almost exclusively by overseas air crew.