On Thursday Sen. John McCain will present the U.S. Hispanic Chamber of Commerce Lifetime Achievement Award to his fellow Vietnam veteran and close friend, Everett Alvarez Jr.
Alvarez was the first American aviator shot down over Vietnam and was the longest-held prisoner of war there, detained for nearly 9 years.
Alvarez’s wife, Tammy, is expected to receive the award on behalf of her husband, who had planned to accept it personally, but was recently hospitalized after suffering an aneurysm.
The presentation will take place at the Hispanic Chamber’s annual legislative summit gala in Washington, D.C.
For the Arizona senator and 2008 Republican presidential nominee, it will be a meaningful event to honor the man he calls "Ev."
“Ev was very brave,” McCain said in an interview Wednesday with Fox News Latino. “Ev is a person who epitomizes what’s great in American men and women who serve our nation.”
Many Americans who were POWs with Alvarez recalled how he kept their spirits from sinking, how he somehow managed to reflect optimism that they all would be freed.
“Every time we’d feel sorry for ourselves, we thought about Ev, who’d been prisoner longer than everyone," McCain told FNL. "He never wavered. He was always loyal to his country.”
Alvarez and McCain, like other POWs, were handcuffed, beaten and tortured. Alvarez spent 15 months in solitary confinement, almost starving after eating only feathered blackbirds, according to published reports.
The POWs tried to survive and stay sane in their isolated quarters by tapping on the walls to send messages to one another, especially as one of their number was about to go through a round of beatings.
“We developed a tap code to communicate, to help each other through difficult times,” McCain said.
In a 2014 BBC News interview, Alvarez, the grandson of Mexican immigrants, said the horror of captivity brought lessons he tried to apply to life in freedom.
"It's about character," Alvarez told the BBC. "Character is the all-encompassing description of a person's moral sense of ethics, of responsibility, of commitment, of loyalty. It's a sense of personal integrity and honor."
And of the loyalty the prisoners felt to one another while in Vietnam.
Alvarez said, "We had a philosophy that you didn't ever let your fellows down. If they couldn't take care of themselves, you took care of them, because you knew darned well they would do the same."
McCain refused a Vietnamese offer to release him from captivity because, he said, he could not in good conscience leave before Alvarez.
“I wasn’t going to leave Ev Alvarez when he had been there two and a half years before me,” McCain said.
Alvarez, who was a Navy commander, has received numerous honors, including the Silver Star, two Legions of Merit, the Distinguished Flying Cross, two Bronze Stars, and two Purple Hearts.
After returning to the United States, he served as Deputy Director of the Peace Corps, Deputy Administrator of the Veterans Administration, and Chairman of the CARES Commission.
In 2008, Alvarez was named one of the 25 greatest public servants by the Council for Excellence in Government. A post office in Rockville, Maryland, is named after him.
“He spent a good part of his life continuing to serve his country,” McCain said.
After his military service, Alvarez obtain a law degree and enjoyed success as an author, entrepreneur and executive.
He wrote the book, “Chained Eagle,” about his Vietnam captivity, and “Code of Conduct,” about building a new life after being set free. In 2014, Secretary of Defense Chuck Hagel appointed him to the Vietnam War Commemoration Advisory Council.
Alvarez and McCain only strengthened their relationship after leaving Vietnam.
“The closest of bonds of friendship that you can imagine were forged under those difficult circumstances,” McCain said. “It’s hard to describe the bonds of friendship that were forged.”
McCain told FNL that he and Alvarez see each other often and know each other’s wives and children well. One of Alvarez's sons also joined the military, serving in Iraq as a Navy doctor.
“[Alvarez] is modest,” McCain said. “He came from a poor family background and became a great American success story. He is typical of many Hispanics who joined the military."
The senator added, "He does not consider himself a hero, but he's a role model and inspiration.”
Elizabeth Llorente is Senior Reporter for FoxNews.com, and can be reached at Elizabeth.Llorente@Foxnews.com. Follow her on Twitter @Liz_Llorente.