Frank Buckles enlisted for World War I at 16 after lying about his age. He made it home again and ultimately became that war's last surviving U.S. veteran, campaigning for greater recognition for his comrades-in-arms before dying at 110.
That marks the end of a war that claimed 8 million dead and 21 million wounded. Many of them died in the mud of Belgium and the mosquito laden coasts of the Dardanelles, or some forgotten wasteland on the Russian Steppe. Some died from U-boat sinking their ships, or in the massive naval battle off Jutland, or from poison gas clouds streaming across battlefields, or simply from marching directly at a MG08 after going "over the top."
It was a war were brave men were led by inept generals who were fighting the previous war. It was a war where on July 1st 1916 57,470 men were wounded and 19,240 were killed most of them in the first hour of the Battle of the Somme. That is 7 times the number that died on D-day and 5 times more then died at Shiloh. The 10 month battle of Verdun alone cost the lives of 306,000 men. If the next war wasn't so much more horrific than WWI would have been the greatest tragedy of the 20st century.
The bad part is there probably would never had been a WW2 if WWI wasn't so horrific and prolonged. If there weren't so many dead then Britain and France might have been more lenient on Germany at the peace table. Maybe a wall-paper hanger and no talent artist from Austria would have stuck to his craft instead of unleashing a war that would claim as many as 80 million people. Maybe the son of a cobbler from the nation of Georgia would have followed his fathers trade instead of becoming one of the great monsters of history. In fact if Russia wasn't so devastated by WWI the Soviets might never had come to power and there would never had been a Cold War.
The death of Pvt. Buckles marks the end of an era that will be remembered always but will hopefully never be repeated again.