State Rep. Dan Caulkins (R-Weldon) recently reflected on the 78th anniversary of D-Day.

The date represents the Allied troops' invasion of Normandy, which occurred on June 6, 1944, during World War II.

"Exactly 78 years ago, the United States and her allies undertook the largest single-day invasion in history," Caulkins said in a Facebook post. "Over the course of June 6, 1944, Allied forces managed to establish a beachhead on the heavily defended shores of France, opening up a new front and dealing a crippling blow to the forces of Nazi Germany."

President Dwight Eisenhower originally selected June 5 as the day for the invasion, according to History.com. But, weather issues caused a 24-hour delay of the operation.

"You are about to embark upon the Great Crusade, toward which we have striven these many months," Eisenhower said to his troops on June 5, after a meteorologist predicted improved conditions for the following day. Eisenhower gave the go-ahead for Operation Overlord: "The eyes of the world are upon you."

"The Normandy beaches were chosen by planners because they lay within the range of air cover, and were less heavily defended than the obvious objective of the Pas de Calais, the shortest distance between Great Britain and the continent," Army.mil said. "Airborne drops at both ends of the beachheads were to protect the flanks, as well as open up roadways to the interior. Six divisions were to land on the first day; three U.S., two British, and one Canadian." Two more British and one U.S. division followed.

People often wonder what the "D" in "D-Day" stands for. The answer might be more mundane than most expect. Army planners used the terms "H-hour" and "D-day" during World War I as placeholders to refer to hours and dates of operations, according to PBS. This was before they had official start times for the operations or to keep the plans secret. The "D" in "D-Day" might simply stand for the "day" of the invasion, PBS said.