WASHINGTON -

The next time a flight attendant reminds you there's no smoking on the plane or you witness a teenager getting carded at a liquor store, think of Frank Lautenberg.

The Democratic senator from New Jersey left his mark on the everyday lives of millions of Americans, whether they know it or not. In the 1980s, he was a driving force behind the laws that banned smoking on most U.S. flights and made 21 the drinking age in all 50 states.

Lautenberg, a multimillionaire businessman who became an accomplished — if often underestimated — politician, died after 4 a.m. Monday at a New York hospital after suffering complications from viral pneumonia.

At 89, he had been the oldest person in the Senate and the last remaining World War II veteran.

He served nearly three decades in the Senate in two stints, beginning with an upset victory in 1982 over Republican Rep. Millicent Fenwick, the pipe-smoking, pearl-wearing patrician who was the model for the cartoon character Lacey Davenport in "Doonesbury."

Possessed with neither a dynamic speaking style nor a telegenic face, he won his last race in 2008 at age 84, becoming the first New Jersey person ever elected to five Senate terms.

"People don't give a darn about my age," Lautenberg said then. "They know I'm vigorous. They know I've got plenty of energy."

Over the years, Lautenberg worked to secure hundreds of millions of dollars for mass transit projects in New Jersey and became an ardent defender of Amtrak.

He was the author of a 1984 law that threatened to withhold federal highway money from states that did not adopt a drinking age of 21, a measure that passed amid rising alarm over drunken driving. At the time, some states allowed people as young as 18 drink.

By 1988, every state was in compliance with the law, which has been widely credited with reducing highway deaths.

A former smoker, Lautenberg was one of two prime sponsors of the 1989 law that banned smoking on all domestic flights of less than six hours, one of several anti-smoking laws he championed and one that helped pave the way for today's numerous restrictions on where people can light up.

Lautenberg had announced in February that he would not seek a sixth term. A longtime advocate of gun control, he returned to the Senate in April despite being in poor health for several votes on gun legislation favored by President Barack Obama, most Democrats and a handful of Republicans. He voted in favor of enhanced background checks for gun purchases and to reinstate a ban on assault-style weapons. Both measures failed.

Wheelchair-bound, he received warm greetings from several colleagues on the Senate floor. He also voted to move along the nomination of a new EPA commissioner, Gina McCarthy.

"Frank was a passionate public servant who was not afraid to fight and vote for what he believed in. He loved the Senate," said Sen. Patty Murray, D-Wash. "He retired once but service called him back, and until the very end of his life, Frank made the trip from New Jersey to D.C. to fight for the issues he believed in and the people he represented. He gave everything he had to public service."

Republican Gov. Chris Christie, whom the Democrat Lautenberg frequently criticized, will appoint a successor and a special election will determine a replacement. Newark Mayor Cory Booker had announced his intention to run and had raised some $2 million.

Along with Lautenberg's legislative accomplishments, he had a string of electoral coups, including his upset over Fenwick, whom he called "the most popular candidate in the country," and a victory in a strange, abbreviated, back-from-retirement campaign 20 years later.

He initially retired in 2000 after 18 years in the Senate, saying he did not have the drive to raise money for a fourth campaign. He served on the boards of three companies, two graduate schools and the U.S. Holocaust Memorial Museum.

But New Jersey Democrats recruited Lautenberg out of retirement in September 2002 as an 11th-hour replacement for Robert Torricelli, Lautenberg's longtime rival, who had abandoned his re-election bid just five weeks before Election Day.

Republicans went to court to prevent what they called the Democratic Party's ballot "switcheroo." When that failed, they attacked Lautenberg as a political relic ill-suited for dangerous times.

But Lautenberg surged to an easy win over Republican Douglas Forrester and returned to the Senate in 2003 at age 78, resuming his role as a leading liberal, and he made it clear that his return to office was no mere cameo.

When the Democrats regained a Senate majority in 2007, he returned to the powerful Appropriations Committee, on which he had served for 15 years. Then, in the fall of 2008, he beat back a Democratic primary challenge.

He was back in the headlines in December that year — this time as an apparent victim.

After Wall Street money manager Bernard Madoff was accused of running a $50 billion fraud scheme, Lautenberg's family foundation said the bulk of its investments were managed by him. A lawyer for the foundation declined to discuss the amount of any possible losses, but tax records in 2006 indicated Madoff managed more than 90 percent of the foundation's nearly $14 million in assets.

Lautenberg first gained prominence as chairman and CEO of Automatic Data Processing, a New Jersey-based payroll services company he had founded with two friends in 1952. It became one of the largest such companies in the world.

He was first elected to the Senate in 1982, during the presidency of Ronald Reagan. Working his way up the seniority ladder, Lautenberg managed to carve out influence on the environment and transportation, two issues that matter greatly to New Jersey, the nation's most densely populated state.