Republican Gov. Chris Christie would appoint a successor to Lautenberg.
Lautenberg was a staunch gun control advocate and frequent critic of the tobacco industry, and he fought for greater government spending on transportation and the environment. He wrote the laws banning smoking on domestic airline flights and setting the national minimum drinking age of 21.
A longtime advocate of gun control, Lautenberg returned to the Senate in April despite being in poor health for several votes on gun legislation favored by 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."
Along with Lautenberg's legislative accomplishments, he had a string of electoral coups, including an upset over Republican Rep. Millicent Fenwick in his first race for Senate, 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 US Holocaust Memorial Museum.