Robert Menendez, a congressman who was raised in a New Jersey tenement by parents from Cuba, on Wednesday became the first minority to serve in the U.S. Senate from the Garden State.

Menendez is the sixth Hispanic ever to serve in the Senate and the body's third sitting Hispanic, joining Democrat Ken Salazar of Colorado and Republican Mel Martinez of Florida.

The 52-year-old Democrat relinquished his longtime title of congressman when he took the oath of office during a brief ceremony on the Senate floor.

New Jersey Gov. Jon Corzine chose Menendez last month to serve out the remaining year of his Senate term, passing over several other Democratic congressmen.

Menendez's first vote as senator will be whether to confirm fellow New Jerseyan Samuel Alito to the U.S. Supreme Court. Menendez has said he remains undecided on Alito. The Senate Judiciary Committee is set to vote on Alito's nomination on Jan. 24, and the full Senate is slated to begin debate the following day.

Menendez leaves the House as the third most powerful Democrat, having served as the party's caucus chairman. He is now ranks 100th out of 100 senators in terms of seniority, according to the Senate Historical Office.

Menendez was sworn in by Republican Ted Stevens of Alaska, the Senate's president pro tempore. Vice President Dick Cheney was slated to swear in Menendez but a trip to the Middle East interfered with those plans.

So far, no other Democrats have said they plan to challenge Menendez for a full term in this year's race for the seat. He has a more-than $4 million campaign war chest that will keep most likely opponents at bay.

For Menendez, the day marked the fulfillment of a childhood dream of being a U.S. senator. Born to parents who emigrated from Cuba, Menendez was raised in a Union City, N.J., tenement, and entered politics when he was 20-years old, serving on his local school board. He served as both a state assemblyman and senator, and was the mayor of Union City before being elected to represent the 13th Congressional District in 1992.