These 8 iconic images tell the story of every US conflict from World War I to Afghanistan

World War I ended 100 years ago on Sunday. 

It was a brutal war that lasted more than four years and killed an estimated 8.5 million soldiers and 13 million civilians. 

It was also a war that cemented the US as a world power, rising to the level of the colonial European powers from which so many Americans and their ancestors had fled. 

But the US has been embroiled in war or conflict for much of the century since the Great War ended. 

And the following iconic war photos show that path. 

World War I (1914-1918).

This photo was taken by Paul Popper for Getty Images. It shows British troops running out of their trenches to charge the enemy lines during the bloody Battle of the Somme. Spaces between trenches were branded "no man's land." 

When Americans got to Europe, this is what the fighting looked like. Life in the trenches involved sharing damp, diseased quarters with dead bodies and making slow, if any progress. 

The Great War between the Allied and Central Powers involved more than 30 countries. It's estimated that 8.5 million soldiers and 13 million civilians were killed during the war. 

World War II (1939-1945).

This photo was taken by Jose Rosenthal for the Associated Press. It shows US troops raising the flag on the Japanese island of Iwo Jima, one of the first pieces of Imperial Japanese territory to fall to US hands.

Fifty years after the picture was taken, the Associated Press wrote that it may be the world's most widely reproduced.

But half of the six soldiers depicted died — among 6,821 Americans — on the very same island they claimed: Franklin Sousley, Michael Strank, and Harlon Block.

The Second World War between the Allied and Axis Powers killed approximately 40 to 50 million people, making it the deadliest war in history. 

Korean War (1950-1953).

This photo was taken by R.V. Spencer for Getty Images. It shows a Korean girl carrying her brother past a stalled M-26 tank in 1951. 

The Korean War began in June 1950 when North Korea, backed by the Soviet Union and China, invaded South Korea, which was backed by the US.

The fighting lasted until 1953, and was devastating to the local population, with approximately 1.6 million civilian casualties on both sides. The war, however, is still technically ongoing, as there was never a peace treaty.