There was never any doubt about the bravery of Sgt William Shemin and Pvt Henry Johnson, but it took almost 100 hundred years for it to be officially recognised.
Campaigners for the two US soldiers - one of them Jewish, one of them black and a member of the so-called Harlem Hellfighters – had long claimed that discrimination and bigotry had stood in the way of them being honoured.
On Tuesday, the two men were finally being posthumously given the Medal of Honour for their actions in rescuing comrades amid the misery and death of the battlefields of France.
The Associated Press said Mr Shemin repeatedly dodged gunfire to pull wounded colleagues to safety, while Mr Johnson managed to save a friend from his all-black regiment while single-handedly fighting off a surprise German attack.
President Barack Obama recognised the men with the highest award for bravery for their actions on the field. Advocates for the two men led Congress to pass an exemption from Medal of Honour rules that specified that such actions have to have taken place within five years to be considered.
"Nobody who serves our country should ever be forgotten," Mr Obama said at the ceremony in Washington.
Ms Shemin's daughter, Elsie Shemin-Roth of St Louis, worked for years to gather documents in support of the bid for her father and accepted the award from Mr Obama on his behalf.
In the early 2000s, she learned of a law that reviewed cases of Jews who may have been denied medals they earned in World War II and fought for passage of a law to provide similar reviews for Jewish World War I veterans, the AP said.
William Shemin's daughter said her father was the victim of anti-Semitism
"This was anti-Semitism, no question about it," Ms Shemin-Roth, who is in her 80s, said in an interview in December when Congress passed the exemption for her father, who died in 1973.
She added: "Now a wrong has been made right and all is forgiven."
Mr Johnson's supporters pushed for the Medal of Honour for decades, with New York Senator Chuck Schumer taking up the case and initially being rebuffed for lack of documentation.
His staff picked up the case again years later when a trove of military records became available online, including a communique from Gen. John Pershing describing Johnson's brave acts after coming under attack by at least 12 German soldiers while on night sentry duty on May 15 1918.
Henry Johnson died in penury
"While under intense enemy fire and despite receiving significant wounds, Johnson mounted a brave retaliation resulting in several enemy casualties," the White House said in a statement.
"When his fellow soldier was badly wounded, Private Johnson prevented him from being taken prisoner by German forces.
"Private Johnson exposed himself to grave danger by advancing from his position to engage an enemy soldier in hand-to-hand combat. Displaying great courage, Private Johnson held back the enemy force until they retreated."
Mr Johnson, a Virginia native who worked as a train station porter in Albany, enlisted in the 369th, a New York National Guard unit based in Manhattan. The "Harlem Hellfighters," as the unit became known, served under French command because US armed forces were segregated at the time.
Mr Johnson was the French Croix de Guerre avec Palme, France's highest award for valour, for his actions.
But it took him much longer to be recognised by the US; he was posthumously awarded the Purple Heart in 1996 and the Distinguished Service Cross in 2002.
Devastated by his wartime injuries, he died a destitute alcoholic at the age of 32 at a veterans' hospital in Illinois in 1929. New York National Guard Command Sgt Maj Louis Wilson accepted the medal on Mr Johnson's behalf.