“June 6, 2021 marks the 77th Anniversary of D-Day, when American, British and Canadian forces landed on the beaches of Normandy, France, in the largest land, air and sea operation to every have taken place.”
https://www.dday.org/overview/
Learn more:
https://www.nationalww2museum.org/war/topics/d-day
https://www.army.mil/d-day/history.html
https://www.history.navy.mil/our-collections/photography/wars-and-events/world-war-ii/d-day.html
https://www.nationalmuseum.af.mil/visit/Museum-Exhibits/Fact-Sheets/Display/Article/1789416/operation-overlord-d-day/
https://coastguard.dodlive.mil/2014/06/5-facts-you-may-not-know-about-the-coast-guard-at-normandy/