COLUMBIA, S.C. (AP) -- Former U.S. Sen. Strom Thurmond of South Carolina, a one-time Democratic segregationist who later helped fuel the rise of the modern conservative Republican Party in the South, died Thursday night. He was 100, the oldest and longest-serving senator in history.

Thurmond died at 9:45 p.m., his son Strom Thurmond Jr. said. He had been living in a newly renovated wing of a hospital in his hometown of Edgefield since he returned to the state from Washington, D.C., earlier this year.

Age took its inevitable toll on Thurmond as he neared retirement, and he was guided through the Capitol in a wheelchair. Yet he wielded political power virtually to the end, prevailing upon President Bush to appoint his 29-year-old son, Strom Jr., as U.S. Attorney in South Carolina in 2001.

Thurmond is "beyond criticism" in South Carolina, Furman University political scientist Don Aiesi said as the senator's health declined and he underwent a series of hospitalizations late in his congressional tenure. "Strom is the most venerable of institutions here."

In a political career that spanned seven decades, Thurmond won his first election in 1928, to local office, and his last in 1996, to his eighth Senate term. "We cannot and I shall not give up on our mission to right the 40-year wrongs of liberalism," he said during his last campaign. "The people of South Carolina know that Strom Thurmond doesn't like unfinished business."

His voting record was pro-defense, anti-communist and staunchly conservative. His devotion to constituent services was legendary. He was a lifelong physical fitness buff, who shunned tobacco and alcohol and was known for his vigorous handshake. He had a storied, lifelong reputation as a ladies' man.

Thurmond ran for president as a Dixiecrat in 1948 and won 39 Southern electoral votes as part of a states-rights uprising against President Harry Truman's support for civil rights. Nearly a decade later, he set the Senate record for filibustering when he spoke for a straight 24 hours and 18 minutes against a bill to end discrimination in housing.

Ironically, his presidential campaign sparked controversy more than a half-century later, when then-Majority Leader Trent Lott declared at Thurmond's 100th birthday party that voters of Mississippi were proud to have supported the South Carolinian when he ran for the White House. "If the rest of the country had followed our lead, we wouldn't have had all these problems over all these years either," added Lott, who was forced to step down as the Senate's Republican leader in the ensuing uproar.

Thurmond's racial politics changed over the years as blacks began voting in large numbers. He became the first Southern senator to hire a black aide, supported the appointment of a black Southern federal judge and voted to make Martin Luther King Jr.'s birthday a national holiday.

His outlook seemed far different a half century ago, when he ran for president.

"I want to tell you," he declared in one speech in 1948, "that there's not enough troops in the Army to force the Southern people to break down segregation and admit the Negro race into our theaters, into our swimming pools, into our homes and into our churches."

Thurmond grew up a Democrat -- his father once ran for office -- but switched to the GOP in 1964 to support Barry Goldwater's conservative campaign for the White House.

He said at the time he had made the move because Democrats were "leading the evolution of our nation to a socialistic dictatorship."

Like other Southern states, South Carolina had been a one-party Democratic state since the end of Reconstruction nearly a century earlier. Thurmond's switch anticipated a broader trend. By the 1990s, the South favored the GOP, and Republican candidates generally triumphed in statewide races in South Carolina.

The first time he ran as a Republican, in 1966, he won easily.

In 1968, Thurmond played a pivotal role in executing the "Southern Strategy" that helped Richard Nixon win the White House. The South Carolinian helped hold Southern delegates in line at the GOP convention when a charismatic conservative, Ronald Reagan, made a late play for the nomination. In the general election, he sought to blunt George Wallace's third-party candidacy in the South, arguing that anything but a vote for Nixon would help elect a liberal Democrat, Hubert Humphrey.

Born Dec. 5, 1902, in Edgefield, S.C., James Strom Thurmond -- Strom was his mother's maiden name -- was elected county school superintendent, state senator and circuit judge before enlisting in the Army in World War II. He landed in Normandy as part of the 82nd Airborne Division assault on D-Day, and won five battle stars and numerous other awards.

The war over, he returned home to resume his political career and won election as governor in 1946. His record was progressive by contemporary standards for a Southern Democrat. He pushed for repeal of the poll tax and boosted education spending.

He lost a race in South Carolina for the only time in his career four years later, when he challenged incumbent Sen. Olin Johnston for renomination. In defeat, he returned home to practice law.

But in 1954, Sen. Burnet Maybank died unexpectedly. When party officials tapped a state lawmaker to run for the post, Thurmond challenged as a write-in candidate, saying the voters, not the party's leaders, should decide who got the nomination. To underscore his credentials as an insurgent, he pledged to resign his seat before seeking re-election in 1956.

He won, the only person in history to capture a seat in Congress by write-in. Two years later, he kept his pledge to resign before running for the four years remaining in the term.

His presidential race and write-in victory behind him, Thurmond arrived in Washington with a nationwide reputation. The civil rights movement was gathering steam, but he held fast to his segregationist views for years.

He was a leader in drafting the Southern Manifesto of 1956, in which Southern lawmakers vowed resistance to the Supreme Court's unanimous school desegregation order. In 1957, he staged his record nonstop filibuster against housing legislation that he denounced as "race mixing."

Ironically, in earlier decades, Thurmond's segregationist views were more nuanced than those held by other Southern politicians.

As governor, he called for forceful prosecution after a black man, a murder suspect, was lynched by a mob. The result was a trial at which 31 white men were defendants.

His 1950 defeat came at the hands of an opponent who made an issue of Thurmond's gubernatorial appointment of a black physician to a state medical advisory board.

Like many one-time segregationists, Thurmond insisted the issue wasn't race but "federal power vs. state power" -- though the state power he wanted to preserve was the power to segregate.

"The question of integration was only one facet of that matter," he said in a November 1992 interview.

Showing how much his world had changed, in 1977, Thurmond's young daughter, Nancy, 6, enrolled in a public school in Columbia, S.C., that was 50 percent black. The girl's teacher also was black.

Thurmond's first wife, Jean Crouch, was 23 years his junior. The couple married in 1947, and she died of a brain tumor in 1960.

His second wife, former beauty queen Nancy Moore, was 44 years younger than Thurmond when they were married in 1968. Thurmond was 68 when their first child, Nancy, was born. The couple had three other children before separating in 1991: Strom Jr., Juliana and Paul. Nancy died in 1993 after being struck by a car.