Henry Oliver Hansen (December 14, 1919 – March 1, 1945) was a United States Marine Corps sergeant who was killed in action during the Battle of Iwo Jima in World War II.

He was a member of the patrol that captured Mount Suribachi, where he helped raise the first U.S. flag on Iwo Jima on February 23, 1945.

[3] Hansen is one of three men who were originally identified incorrectly as flag-raisers in the photograph (the others being John Bradley and Rene Gagnon).

He landed with his rifle company and battalion at the southern end of Iwo Jima where Mount Suribachi is located.

[citation needed] On February 23, 1945, Lieutenant Colonel Chandler W. Johnson, commander of the 2nd Battalion, 28th Marine Regiment, ordered a platoon-size patrol to climb up 556-foot Mount Suribachi.

Captain Dave Severance, E Company's commander, assembled the remainder of his Third Platoon and other members of the battalion headquarters including two Navy corpsmen and stretcher bearers.

First Lieutenant Harold Schrier, E Company's executive officer, was handed the Second Battalion's American flag from Lt.

Charles Lindberg (Platoon Sergeant Ernest Thomas was watching inside the group with a grenade in his hand while Pvt.

Ward, and Third Platoon corpsman John Bradley helped make the flagstaff stay in a vertical position.

The men at, around, and holding the flagstaff which included Schrier's radioman Raymond Jacobs (assigned to patrol from F Company), were photographed several times by Staff Sgt.

Thomas to report early the next morning to Marine Lieutenant General Holland Smith aboard Navy Vice Admiral Richmond K. Turner's flagship the USS Eldorado (AGC-11) about the flag raising on Mount Suribachi.

Thomas met with the two commanders and during an interview with a CBS news broadcaster aboard ship he named Lt. Schrier, Sgt.

A 96 by 56 inch flag was obtained from a ship docked on shore and brought up to the top of Mount Suribachi by Pfc.

Harold Keller (both members of Lt. Schrier's patrol)[13] raised the larger flag at the same time three Marines and Pfc.

After the replacement flag was raised, sixteen Marines, including Schrier and Hansen, and two Navy corpsmen (John Bradley and Gerald Ziehme from the 40-man patrol) posed together for Rosenthal around the base of the flagstaff.

On March 14, an American flag was officially raised up a flagpole by orders of Lieutenant General Holland Smith at the V Amphibious Corps command post on the other side of Mount Suribachi where the 3rd Marine Division troops were located, and the second flag which was raised on February 23 on Mount Suribachi came down.

Thomas, and the three second flag-raisers who were killed on Iwo Jima were buried in the 5th Marine Division cemetery on the island.

The battle of Iwo Jima officially ended on March 26, 1945, and the next day the 28th Marines left the island for Hawaii.

Hansen's final burial was at the National Memorial Cemetery of the Pacific near Honolulu on the island of Oahu in Hawaii.

He was questioned the same day by a Marine public information officer about the identities of the six flag raisers in the photograph.

Bradley were ordered to Marine Headquarters in Washington D.C. Bradley, who was recovering from his wounds at Oakland Naval Hospital in Oakland, California, was transferred to Bethesda Naval Hospital at Bethesda, Maryland, where he was shown Rosenthal's flag-raising photograph and was told he was in it.

Hayes that the identities were made public on April 8 and would not be changed, and to not say anything about it anymore (the officer later denied that Pfc.

[15][3] A Marine Corps investigation of the identities of the six second flag-raisers began in December 1946 and concluded in January 1947 that it was Cpl.

[16][17] A third Marine Corps investigation into the identities of the six second flag-raisers concluded in October 2019, that Harold Keller was in the Rosenthal's photograph in place of Rene Gagnon (fifth from left).

[18] Harold Schrier, Charles Lindberg, and Lou Lowery, from the patrol that raised the first flag on Mount Suribachi, attended the dedication ceremony as guests.

President Dwight D. Eisenhower sat upfront during the dedication ceremony with Vice President Richard Nixon, Secretary of Defense Charles E. Wilson, Deputy Secretary of Defense Robert Anderson, and General Lemuel C. Shepherd, the 20th Commandant of the Marine Corps.

Moreau, U.S. Marine Corps (Retired), President, Marine Corps War Memorial Foundation; General Shepherd, who presented the memorial to the American people; Felix de Weldon, sculptor; and Richard Nixon, who gave the dedication address.

[25][26] Hank Hansen is featured in the 2006 Clint Eastwood movie Flags of Our Fathers, where he is played by American actor Paul Walker.