Question: What is the year of the event that occured first, the Battle of Gettysburg was fought, or Operation Overlord was launched?

Context articles: Overlord (film)
Battle of Gettysburg
Operation Perch
Operation Charnwood
Battle of Long Khanh
Operation Bolero
Battle of Saipan
American airborne landings in Normandy
Operation Overlord
Operation Totalize

Overlord is a 1975 black-and-white film written and directed by Stuart Cooper.
 Set around the D-Day invasion ('Operation Overlord'), "Overlord" is a war film about a young soldier's meditations on being part of the war machinery, and his premonitions of death.
 The film was entered into the 25th Berlin International Film Festival, where it won the Silver Bear - Special Jury Prize.
The Battle of Gettysburg ( , with an sound) was fought July 1–3, 1863, in and around the town of Gettysburg, Pennsylvania, by Union and Confederate forces during the American Civil War.
 The battle involved the largest number of casualties of the entire war and is often described as the war's turning point.
 Union Maj. Gen. George Meade's Army of the Potomac defeated attacks by Confederate Gen. Robert E. Lee's Army of Northern Virginia, halting Lee's invasion of the North.
Operation Perch was a British offensive of the Second World War which took place from 7 to 14 June 1944, during the early stages of the Battle of Normandy.
 The operation was intended to encircle and seize the German occupied city of Caen, which was a D-Day objective for the British 3rd Infantry Division in the early phases of Operation Overlord.
 Operation Perch was to begin immediately after the British beach landings with an advance to the south-east of Caen by XXX Corps.
 Three days after the invasion the city was still in German hands and the operation was amended.
 The operation was expanded to include I Corps for a pincer attack on Caen.
Operation Charnwood was an Anglo-Canadian offensive that took place from 8 to 9 July 1944, during the Battle for Caen, part of the larger Operation Overlord (code-name for the Battle of Normandy), in the Second World War.
 The operation was intended to at least partially capture the German-occupied city of Caen (] ), which was an important objective for the Allies during the opening stages of Overlord.
 It was also hoped that the attack would forestall the transfer of German armoured units from the Anglo-Canadian sector to the lightly screened American sector, where a major American offensive was being planned.
 The British and Canadians advanced on a broad front and by the evening of the second day had taken Caen up to the Orne and Odon rivers.
The Battle of Long Khanh (6–7 June 1971) was fought during the Vietnam War between elements of 1st Australian Task Force (1 ATF) and the Viet Cong and North Vietnamese Army during Operation Overlord.
 The fighting saw Australian infantry from 3rd Battalion, Royal Australian Regiment (3 RAR) attack a heavily fortified communist base camp in Long Khanh Province, while Centurion tanks providing close support crushed many bunkers and their occupants.
 Regardless, the Viet Cong fought hard to delay the Australian advance and although the bunker system was subsequently captured, along with a second system further south, the Australians suffered a number of casualties and the loss of a UH-1 Iroquois helicopter.
 With the Australians unable to concentrate sufficient combat power to achieve a decisive result, the bulk of the Viet Cong and North Vietnamese force successfully withdrew intact, although they probably sustained heavy casualties in the process.
Operation Bolero was the commonly used reference for the code name of the United States military troop buildup in the United Kingdom during World War II in preparation for the initial cross-channel invasion plan known as Operation Roundup, to be implemented in mid-1943, or for its lesser contingency alternative, Operation Sledgehammer, to be executed in the fall of 1942 in the event of German setbacks or to ease Axis pressure on the Eastern Front.
 ("Bolero" was the code name used in official communications to stand in for "United Kingdom" when describing the theater or movements.)
 What later became the Bolero plan – the buildup of a strategic air force in Great Britain in preparation for Roundup – was first submitted by Commanding General of the U.S. Army Air Forces, Henry H. Arnold, to General George Marshall, the U.S. Army Chief of Staff, on April 12, 1942, and set in motion a huge movement of men and material that laid the groundwork for Operation Overlord.
The Battle of Saipan was a battle of the Pacific campaign of World War II, fought on the island of Saipan in the Mariana Islands from 15 June to 9 July 1944.
 The Allied invasion fleet embarking the expeditionary forces left Pearl Harbor on 5 June 1944, the day before Operation Overlord in Europe was launched.
 The U.S. 2nd Marine Division, 4th Marine Division, and the Army's 27th Infantry Division, commanded by Lieutenant General Holland Smith, defeated the 43rd Infantry Division of the Imperial Japanese Army, commanded by Lieutenant General Yoshitsugu Saito.
The American airborne landings in Normandy were the first American combat operations during Operation Overlord, the invasion of Normandy by the Western Allies on June 6, 1944, during World War II.
 Around 13,100 American paratroopers of the 82nd and 101st Airborne Divisions made night parachute drops early on D-Day, June 6, followed by 3,937 glider troops flown in by day.
 As the opening maneuver of Operation Neptune (the assault operation for Overlord) the two American airborne divisions were delivered to the continent in two parachute and six glider missions.
Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful invasion of German-occupied Western Europe during World War II.
 The operation was launched on 6 June 1944 with the Normandy landings (Operation Neptune, commonly known as D-Day).
 A 1,200-plane airborne assault preceded an amphibious assault involving more than 5,000 vessels.
 Nearly 160,000 troops crossed the English Channel on 6 June, and more than two million Allied troops were in France by the end of August.
Operation Totalize (also spelled Operation Totalise in recent British sources) was an offensive launched by Allied troops in the First Canadian Army during the later stages of Operation Overlord, from 8 to 9 August 1944.
 The intention was to break through the German defences south of Caen on the eastern flank of the Allied positions in Normandy and exploit success by driving south, to capture the high ground north of the city of Falaise.
 The goal was to collapse the German front and cut off the retreat of German forces fighting the Allied armies further west.
 The battle is considered the inaugural operation of the First Canadian Army, which had been activated on 23 July.