Sen. Daniel K. Inouye today becomes the third-longest-serving senator in U.S. history, a landmark for the powerful lawmaker who has held a seat in Congress for as long as Hawaii has been a state.

Inouye has been in office in the U.S. Senate for nearly 47 years. He passes Sen. Edward Kennedy in seniority following the Aug. 25 death of his longtime Democratic colleague from Massachusetts.

"It's an achievement to think I lasted this long," said Inouye, who manages much of the nation's money as chairman of the Senate Appropriations Committee. "During that time, I've witnessed many historic events, participated in some of them and I've found that each day was a new and exciting one."

The 85-year-old senator who lost his right arm in combat during World War II went on to serve as a member of the Watergate investigative committee in the 1970s and chairman of the Iran-Contra probe in the 1980s.

In recent years, Inouye has become known for his ability to bring federal money to his home state, and he even declared himself "the No. 1 earmarks guy in the U.S. Congress" in August.

As the first Japanese-American to serve in both the Senate and House of Representatives, Inouye said he's proud to have helped advance civil rights.

"Because of my color and ancestry, people expected me to play a role," Inouye said. "To find myself today serving as chairman of the Appropriations Committee is a great honor."

With 17,095 days in the Senate, Inouye trails only West Virginia Sen. Robert Byrd and the late South Carolina Sen. Strom Thurmond in career longevity. Inouye will catch up with Thurmond in eight months, and he's still about four years behind the 91-year-old Byrd.

Inouye has been able to expand his authority because he shows respect for Republicans as well as Democrats, said Robbie Alm, executive vice president for Hawaiian Electric Co. who worked as a legislative assistant for the senator 30 years ago.

"He's served so long in part because he's able to walk through that building without having to worry that there are a lot of knives aimed at his back," Alm said.

By all accounts, Inouye remains mentally sharp as he seeks his ninth senatorial term next year.

"One of the things Dan has been able to avoid is any sign of losing intelligence or awareness or any of the things we stereotype with old age. As long as that's the case, people's memories of him will be very strong," University of Hawaii political scientist Neal Milner said.

Inouye was Hawaii's first full member in the House of Representatives when he took office the same day the Islands became a state 50 years ago, on Aug. 21, 1959. Three years later, he was elected to the Senate.

As he moved up in seniority and influence, he has been able to help steer billions of dollars toward Hawaii on projects including astronomy facilities, university research, the military's Pacific Command headquarters and the Pacific Missile Range.

"He's done so much for us in Hawaii for so long, that sometimes we forget that he's become a true national leader, paving the way for so many people and influencing policy on matters of war and peace," said Brian Schatz, chairman of the Hawaii Democratic Party.

Hawaii pulls down the second-most money per capita in earmarks, at $227 per person, the conservative watchdog group Taxpayers for Common Sense reported in 2008. Hawaii trails only Alaska in per capita earmark spending.