CHARLESTON, W.Va. -- Sen. Jay Rockefeller and West Virginia were an odd mix at first -- a Harvard-educated native New Yorker from one of the nation's richest families arriving in one of the poorest states.

Through a half century of public service, he made it work. And as he heads into retirement as the last member of the Rockefeller family dynasty in political office -- and the only Democrat -- the five-term U.S. senator leaves a blueprint for fighting to fix real-life problems for burdened families and to protect the nation's coal miners.

"As this chapter of my Senate career comes to a close, I feel fortunate to have been able to dedicate 50 years to public service," Rockefeller, 77, said in a statement. "I could not imagine a more rewarding career."

Or one that lasted so long in his adopted state. Rockefeller's stay was intended to be brief when he arrived in 1964 to work in an anti-poverty program a few years out of college. He never left, transforming from a volunteer social worker to a career politician.

John D. Rockefeller IV -- universally known as Jay -- was born in New York City in 1937. His father, John D. Rockefeller III, was a well-known philanthropist. Uncles Winthrop (Arkansas) and Nelson (New York) were Republican governors. Another uncle, David Rockefeller, ran Chase Manhattan Bank.

Jay Rockefeller took a different path.

At 27 he moved to the mining community of Emmons in 1964 to participate in the anti-poverty Volunteers in Service to America program. Two years later, he broke from his family's Republican tradition and was elected to the state House of Delegates as a Democrat.

"Because of his good fortune, he could have chosen a very different life," said former President Bill Clinton, who has known Rockefeller since the pair were governors. "Instead of self-indulgence, he chose service to people and places too often left out and left behind.

"West Virginia and America are better off, because as a young man Jay Rockefeller chose a life of service."

A turning point came after Rockefeller's only political defeat in the 1972 governor's race to Republican Arch Moore, whose daughter, Republican Shelley Moore Capito, was elected in November to take Rockefeller's Senate seat.

After the defeat, Rockefeller remained in West Virginia, a decision he called the most important of his career.

He became the first without a theological degree to become president of West Virginia Wesleyan College in 1973. His popularity there translated to a landslide win over Republican Cecil Underwood in the 1976 governor's race.

After first winning election in 1984, Rockefeller served 30 years in the U.S. Senate.

"In a sense, he proved the critics wrong by not leaving," said Robert Rupp, a longtime political science professor at West Virginia Wesleyan. "His longevity in the Senate and his service as governor proves his acceptance."

Rockefeller was the state's junior senator for 25 years, yet carved his own path of influence in Sen. Robert C. Byrd's immense shadow. Byrd died in 2010 as the longest-serving senator in U.S. history, winning an enduring reputation for steering billions of dollars over many decades to boost his impoverished state.

Rockefeller's influence was less showy. As chairman of the Senate Committee on Commerce, Science, and Transportation, he championed consumers' rights, upgrading broadband infrastructure and sponsoring a bill to block companies from tracking online activity of their customers.

Rockefeller also served as head of the committees on Intelligence and Veterans' Affairs.

College studies in Tokyo laid the groundwork for his efforts to bring business from Japan to West Virginia. He has known Toyota's founding family since the 1960s and was instrumental in helping the Japanese automaker pick a Buffalo cornfield for an engine parts plant in 1996. The plant now employs about 1,200 workers.

In 1997, Rockefeller authored legislation that created the Children's Health Insurance Program, which covers more than 40,000 children in West Virginia and 8 million nationwide in poor families with incomes too high to qualify for Medicaid.

Clinton, whose time as Arkansas governor coincided with Rockefeller's tenure as West Virginia governor, said in a statement through his foundation that Rockefeller was a "tremendous ally" during his administration.

Coal companies and their conservative allies accused Rockefeller of being out of touch for defending clean-air regulations and other policies they claimed imperiled tens of thousands of mining jobs. But he still easily won re-election to a fifth term in 2008, even though Barack Obama lost the state.