Seventy-one years ago today, photographer Joe Rosenthal was in the right place at the right time. Just as five Marines and one Navy sailor hoisted an American flag at the summit of Mount Suribachi on Iwo Jima, an island southeast of Japan, Rosenthal raised his Speed Graphic camera and snapped one of the most iconic pictures of all time. Here’s what you need to know about his Pulitzer Prize-winning photo.

1. THE PHOTO ACTUALLY CAPTURED THE SECOND FLAG-RAISING OF THE DAY.

Before Rosenthal took his picture, fellow photographer Sgt. Louis Lowery had been snapping pictures of the first flag raising for Leatherneck magazine.

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Afterward, he decided to go back down the mountain to retrieve different equipment. On the way, he encountered Rosenthal climbing up. Lowery warned Rosenthal that he had missed the flag raising, but Rosenthal decided to go up and grab a few pictures anyway. When he got to the top, he discovered that the Marines had been ordered to replace the flag with a larger one—and that flag-raising is the one that was immortalized in Rosenthal’s picture.

2. SADLY, HALF OF THE SOLDIERS IN THE PICTURE WERE KILLED IN ACTION NOT LONG AFTER THE PHOTO WAS TAKEN.

Harlon Block, age 20, and Michael Strank, age 25, were both killed on March 1. Franklin Sousley, age 19, was shot on March 21. By the time Iwo Jima was secured, there were three surviving soldiers from the group: Rene Gagnon, Ira Hayes, and Navy hospital corpsman John Bradley.

3. DESPITE MANY ARGUMENTS TO THE CONTRARY, THE PHOTO WASN'T STAGED.

The controversy stems from a moment of confusion—you see, Rosenthal wasn’t entirely sure that he had captured the flag raising moment, so afterward, he asked the group of men to pose for a picture beneath the flying stars and stripes. He referred to this as the “Gung Ho” picture. When people saw the picture in the newspapers and congratulated him, Rosenthal assumed the papers had picked up the “Gung Ho” shot, and freely said that he had posed the soldiers for the photo. It wasn’t until later that he realized which photo had become a national sensation. He spent the rest of his life denying that he had staged the flag-raising shot.

4. A FELLOW JOURNALIST WAS SHOOTING FOOTAGE WHILE ROSENTHAL WAS TAKING PICTURES.

You can see some of his footage at the end of this video:

5. IT INSPIRED AMERICANS TO BUY WAR BONDS.

The photo was used in 3.5 million posters for the Seventh War Loan Drive, and the three surviving soldiers were sent on tour to encourage Americans to buy war bonds. It worked—thanks to the patriotism and emotion exuding from the photograph, war bond sales from the Seventh War Loan Drive totaled $26.3 billion, nearly double the original goal.

6. BOTH OF THE FLAGS WERE PRESERVED AND NOW LIVE AT THE NATIONAL MUSEUM OF THE MARINE CORPS.

Both of the flags raised at the summit of Mount Suribachi eventually found their way home and are now displayed on a rotating basis at the Triangle, Virginia, museum. The museum calls them “perhaps the most important artifacts in the care of the National Museum of the Marine Corps.”