Daniel K. Inouye, a Medal of Honor recipient from his service during World War II and, as Hawaii's senior Senator, the longest-serving member of that body, died Monday at the Walter Reed National Military Medical Center from respiratory complications. He was 88.
Inouye's  wife, Irene Hirano Inouye, and his son, Daniel Ken Inouye Jr., were at his side. His office said his final word was "Aloha."
"Our country has lost a true American hero," President Obama said. "Danny represented the people of Hawaii in Congress from the moment they joined the Union. ... Our thoughts and prayers are with the Inouye family."
Senate Majority Leader Harry Reid on the chamber floor Monday night called Inouye "one of the giants of the Senate."
"His commitment to our nation will never be surpassed." added Reid, D-Nevada.
Inouye represented Hawaii in Congress from the time it became a state in 1959. He was initially elected as the state's first House member for two terms and, subsequently, as a senator for nine terms.
But his storied tenure began as a freshman House member - initially with no staff - when he first arrived on Capitol Hill. In 2011, he recalled an early conversation with then-Speaker Sam Rayburn, D-Texas, who had called his office.
"I was there by myself and answered the telephone," Inouye recounted. "And the voice said, 'I'm looking for a Congressman from Hawaii. I can't pronounce his damn name, but his first name is Dan.' I said, 'That's me.' Then he says, 'This is Speaker Rayburn.'"
By the end of his career, Inouye was the most senior member - or president pro tempore - of the Senate, making him third in line for the presidency.
Inouye preferred a reverence for the institution of the Senate over the partisan bombast displayed by many of his colleagues. Although he rarely appeared at press conferences or made speeches on the Senate floor, he had an undeniably commanding presence. His words tended to carry weight when he did speak out on issues.
He chaired four different committees during his Senate tenure: the Intelligence Committee from 1976 to 1979, the Indian Affairs Committee from 1987 to 1995 and 2001 to 2003, the Commerce Committee from 2007 to 2009, and the Appropriations Committee since 2009. Inouye assumed the helm of that panel after the legendary Sen. Robert Byrd, D-W.Va.,  relinquished the gavel. Before chairing the full panel that establishes funding for government programs, he sat at the helm of the Defense Appropriations Subcommittee determining the scope of the nation's military spending.
Inouye was the first Japanese-American to serve in either chamber of Congress. He also had the distinction of serving in the 442nd Regimental Combat Team, a segregated unit of Japanese Americans, during World War II.
The then-War Department had initially determined that the Nisei, second-generation Japanese Americans, were "enemy aliens" prohibited from serving in the military. But after Inouye and other fellow Nisei successfully petitioned the Roosevelt administration to change its policy, the military began to accept them for service on a separated basis.
Inouye was promoted to a sergeant within his first year and eventually became a platoon leader. While fighting Nazi forces in Tuscany in April 1945, Inouye suffered multiple severe injuries but refused to back down. First, he was struck in the abdomen by a bullet that exited his body through his back, missing his spine by inches. Despite the injury, he continued to toss two hand grenades at the opposing forces. But suddenly, a German rifle grenade at close range shattered his right arm. Inouye then threw a third grenade with his still-intact left hand and continued firing a machine gun. It wasn't until a bullet hit his leg that he finally stopped.
Members of his regiment rushed to his aid, but Inouye ordered them back to their positions. "Get back up that hill!" he yelled. "Nobody called off the war!"
His right arm was later amputated - without anesthesia - at a field hospital.
After the war, Inouye earned a total of 16 medals and citations for his service, including the Distinguished Service Cross, the Bronze Star, the Purple Heart and the Medal of Honor.
But he wasn't awarded the last recognition until 2000. None of the Nisei soldiers of the 442nd Regiment ever received the Medal of Honor, the military's highest decoration, even though many considered the battalion among the most heroic in World War II. More than 50 years later, the Distinguished Service Crosses given to Inouye and 21 other members of the regiment were upgraded to the Medal of Honor. Fifteen of the medals were awarded posthumously. President Clinton presented Inouye and the other remaining veterans with the Medal of Honor at the White House.
During the 2002 debate over the Iraq war, Inouye made a rare Senate floor speech - with no prepared remarks - in objection to President Bush's charge that Democrats weren't concerned with national security. The president had said that Senate Democrats' failure to pass legislation creating the Department of Homeland Security suggested they were "more interested in special interests in Washington and not interested in the security of the American people."
"Certainly, I did not vote for him, but he is my president, and it grieves me when my president makes statements that would divide this nation," Inouye said. "This is not a time for Democrats and Republicans to say, 'We got more medals than you, we've lost more limbs than you, we've shed more blood than you.'"
"This is a time when we should be working together, debating this issue," he continued. "It is American to question the president. It is American to debate this issue."
Senate Majority Leader Tom Daschle (D-SD) then dared Mr. Bush to insinuate that Inouye and other veterans serving in the Senate weren't concerned about national security. He demanded for the president's apology.
"The president ought to apologize to Senator Inouye and every veteran who has fought in every war who is a Democrat in the U.S. Senate," Daschle said on the chamber floor.
Inouye first entered the national spotlight when he delivered the keynote address at the chaotic 1968 Democratic National Convention in Chicago. He had been on the Hubert Humphrey campaign's short list for vice presidential candidates that year. And leading Democrats felt Inouye's views as an Asian-American veteran opposed to the Vietnam War carried significance.
"This is my country," Inouye said in his speech. "Many of us have fought hard for the right to say that. Many are now struggling today from Harlem to Da Nang that they may say this with conviction. This is our country."
Inouye's speech ultimately made little impact amid the violent protests and deeply split party that year after the initial frontrunner Robert Kennedy's assassination. But it planted him firmly at the center of American politics for years to come.
Inouye entered the spotlight again during the 1970s as a member of the Watergate Committee probing the alleged criminal activities of the Nixon administration. And in 1987, he chaired another congressional panel investigating executive branch wrongdoing: the Iran-Contra Committee.
The scandal's central figure, Lieutenant Colonel Oliver North of the National Security Council, dominated coverage of the hearings. He stood by his role selling weapons via intermediaries to Iran as a means of aiding the anti-communist Nicaraguan Contras - and made a point of wearing his military uniform bedecked with medals.
On the last day of the committee's proceedings, Inouye scolded North for defending any wrongdoing under a cover of trying to curb the rise of communism in South America and simply following superiors' instructions.
"The uniform code makes it abundantly clear that it must be the lawful orders of a superior officer. In fact, it says: 'Members of the military have an obligation to disobey unlawful orders,'" Inouye said.
Inouye then made a comparison to the Nuremberg Trials, which made North's lawyer, Brendan Sullivan, interrupt in objection. The chairman nonetheless went on to accuse North of following wrongful orders and misleading government officials in the name of patriotism, ending with a quote from Thomas Jefferson about the "spirit of resistance to government."
Inouye's widely praised management of the Iran-Contra hearings later fueled speculation to join Democratic presidential nominee Michael Dukakis's ticket the following year. Some Democrats thought his reputation for righteousness could balance what they considered Dukakis's "sleaze factor."
Inouye was also known for his steadfast loyalty to members on both sides of the aisle. He made headlines in 2008 when he campaigned for embattled Sen. Ted Stevens (R-AK), his longtime Appropriations Committee colleague.
"There are things that are more important than political considerations," Inouye said while on the stump. "And that's friendship."
A source close to Inouye tells Fox News that Inouye wrote Hawaii's Democrat Gov. Neil Abercrombie in his final hours, asking that he appoint freshman Rep. Colleen Hanabusa, D-Hawaii, to his seat, describing it as his "last wish."
Hanabusa lost a three-way race in a special election for to take Abercrombie's House seat in 2010. However, she won the general election in the fall of 2010 and won re-election to a second House term last month.
The appointment of Hanabusa would give Hawaii an all-female Congressional delegation for the moment. New Hampshire will have an entirely female delegation in the new Congress.
Inouye was married for nearly 57 years to Maggie Awamura, who passed away in 2006 after a battle with cancer. They had one son, Ken. In 2008, Inouye married Irene Hirano, the president of the U.S.-Japan Council and former CEO of the Japanese American National Museum in Los Angeles.