WASHINGTON – Sen. Robert C. Byrd, a son of West Virginia coal country who used his mastery of Senate rules and a taste for hardball tactics to become a passionate and often feared advocate for the state and the Senate he loved, died Monday at age 92.

The Democrat’s 51 years in the Senate made him the longest-serving senator in history. His white mane, stentorian voice and flamboyant speeches citing Roman emperors gave him the presence of a man from a grander, distant time.

In many ways, Byrd embodied the changes the nation has undergone in the past half century.

He rose from grinding poverty, overcame an early and ugly association with the Ku Klux Klan, and by force of will made himself a person of authority and influence in Washington.

A one-time segregationist and critic of civil rights legislation, he evolved into a liberal hero as one of the earliest, unrepentant and most vocal foes of the Iraq war and a supporter of the rights of gays to serve in the military.

SENATORS PAY TRIBUTE TO COLLEAGUE

As the Senate opened Monday, Byrd’s desk was draped in black cloth with a bowl of white roses. Flags outside the White House and the Capitol flew at half-staff.

Senators who came to the floor to pay tribute recognized both his longevity – he also cast more votes than any senator in history – and the tenacity with which he defended the traditions and prerogatives of the Senate.

“Sen. Byrd’s ambition was legendary,” said Senate Majority Leader Harry Reid, D-Nev. He recalled how shortly after Byrd first took his oath of office on Jan. 3, 1959, he told a local newspaper that he wanted to someday chair the Senate Appropriations Committee. “Thirty years later, he was – and then lived and served for 21 more,” Reid said.

The stiff and formal Byrd could speak at great length with passion, mixing references to the Roman Empire with emotional memories of his almost seven decades with his late wife, Erma.

Brandishing a copy of the U.S. Constitution that he always carried with him, he resisted any attempt to diminish the role of the Senate, as in the days leading up to the 2003 invasion of Iraq when he was one of the few to stand up against ceding warmaking powers to President George W. Bush.

President Obama said the Senate “has lost a venerable institution, and America has lost a voice of principle and reason.”

A spokesman for the family, Jesse Jacobs, said Byrd died around 3 a.m. at Inova Hospital in Fairfax, Va. He had been hospitalized since last week with what was thought to be heat exhaustion, but more serious issues were discovered, aides said Sunday. No formal cause of death was given.

Byrd often seemed a Senate throwback to a courtlier 19th century. He could recite poetry, quote the Bible, discuss the Constitutional Convention and detail the Peloponnesian Wars – and frequently did in debates.

Yet there was nothing particularly courtly about Byrd’s pursuit or exercise of power.

Byrd was a master of the Senate’s bewildering rules and longtime chairman of the Senate Appropriations Committee, which controls one-third of the $3 trillion federal budget. He was willing to use both to reward friends and punish those he viewed as having slighted him.

“Bob is a living encyclopedia, and legislative graveyards are filled with the bones of those who underestimated him,” former House Speaker Jim Wright, D-Texas, once said in remarks that Byrd later displayed in his office.

HELD NUMEROUS KEY POSITIONS

In 1971, Byrd ousted Sen. Edward Kennedy, D-Mass., as the party’s second in command. Elected majority leader in 1976, he held the post until Democrats lost control of the Senate in 1980. He remained his party’s leader through six years in the minority, then spent another two years as majority leader.

Byrd stepped aside as majority leader in 1989 when Democrats sought a more contemporary television spokesman. “I ran the Senate like a stern parent,” Byrd wrote in his memoir, “Child of the Appalachian Coalfields.” His consolation prize was the chairmanship of the Appropriations Committee.

Within two years, he surpassed his announced five-year goal of making sure more than $1 billion in federal funds was sent back to West Virginia, money used to build highways, bridges, buildings and other facilities, some named after him.

In 2006, with 64 percent of the vote, Byrd won an unprecedented ninth Senate term just months after surpassing South Carolinian Strom Thurmond’s record as its longest-serving member. His more than 18,500 roll call votes were another record.

Byrd seemed to slow after the death of Erma, his wife of almost 69 years, in 2006. At times wistful, he used two canes to walk and needed aides’ help to make his way about the Senate. He often hesitated at unscripted moments. 2009, aides were bringing him to and from the Senate floor in a wheelchair.

In late 2008, he surrendered his chairmanship of the Appropriations Committee.

Byrd’s lodestar was protecting the Constitution. He also defended the Senate in its age-old rivalry with the executive branch, no matter which party held the White House.

Unlike other prominent Senate Democrats such as John Kerry of Massachusetts, who voted to authorize the war in Iraq, Byrd stood firm in opposition – and felt gratified when public opinion swung behind him.

“The people are becoming more and more aware that we were hoodwinked, that the leaders of this country misrepresented or exaggerated the necessity for invading Iraq,” Byrd said.

Byrd’s accomplishments followed a childhood of poverty, and his success on the national stage came despite a complicated history on racial matters. As a young man, he was a member of the Ku Klux Klan for a brief period, and he joined Southern Democrats in an unsuccessful filibuster against the landmark 1964 Civil Rights Act.

He later apologized for both actions, saying intolerance has no place in America. While supporting later civil rights bills, he opposed busing to integrate schools.

CHILD OF APPALACHIAN COAL FIELDS

Robert Carlyle Byrd was born Nov. 20, 1917, in North Wilkesboro, N.C., as Cornelius Calvin Sale Jr., the youngest of five children.

Before he was 1, his mother died and his father sent him to live with an aunt and uncle, Vlurma and Titus Byrd, who renamed him and moved to the coal-mining town of Stotesbury, W.Va.

He graduated from high school but could not afford college. Married in 1936 to high school sweetheart Erma Ora James – with whom he had two daughters – he pumped gas, cut meat and during World War II was a shipyard welder.

Returning to meat cutting in West Virginia, he became popular for his fundamentalist Bible lectures. A grand dragon of the Ku Klux Klan suggested he run for office.

He won his first race – for the state’s House of Delegates – in 1946, distinguishing himself from 12 rivals by singing and fiddling mountain tunes. His fiddle became a fixture; he later played it on the television show “Hee Haw” and recorded an album.

After six years in the West Virginia legislature, Byrd was elected to the U.S. House in 1952 in a race in which his brief Klan membership became an issue. He said he joined because of its anti-communism.

Byrd served three terms in the House before winning his Senate seat in 1958, when Dwight D. Eisenhower was in the White House.

He took a decade of night courses to earn a law degree in 1963, and completed his bachelor’s degree at West Virginia’s Marshall University in 1994 with correspondence classes.

Byrd entered Congress as one of its most conservative Democrats. He was an early supporter of the Vietnam War, and his 14-hour, 13-minute filibuster against the 1964 civil rights bill remains one of the longest ever. His views gradually moderated, particularly on economic issues, but he always sided with his state’s coal interests in confrontations with environmentalists.

His detractors labeled him a racist hillbilly, but over the years he worked to shed that image. When he arrived in the Senate in 1959, he had hired one of the Capitol’s first black congressional aides. When a vote on making Martin Luther King’s birthday a federal holiday came up on the floor of the Senate in 1983, Byrd told an aide, “I’m the only one who must vote for this bill.”

When he became majority whip, Byrd was the third most conservative senator outside the South, but within weeks of assuming whip duties, his voting record began to moderate.

Though he never relinquished his conservative demeanor, he began to support most civil rights legislation, including the Equal Rights Amendment. He also continued to vote with Senate liberals on housing, unemployment benefits, Social Security and public works projects.

“A leadership role is different,” he said, “and one does represent a broader constituency.”

His love of Senate traditions inspired him to write a four-volume history of the chamber. It also led him to oppose laptops on the Senate floor and to object when a blind aide tried bringing her guide dog into the chamber.

In 2004, Byrd got Congress to require schools and colleges to teach about the Constitution every Sept. 17, the day the document was adopted in 1787.