The package -- which passed the House Wednesday -- is expected to be sent to the president for his immediate signature.
The lone dissenting vote was from Wisconsin Democrat Russ Feingold, who has protested the rapid manner in which the bill had been considered in the House and Senate.
The final version of the bill was developed last week in informal negotiations between the bipartisan leadership of both houses, which worked to combine the versions each body has passed over the last two weeks.
The passed version of the bill offers law enforcement broad new powers to combat terrorism, including the ability to request "roving wiretaps," which follow individuals rather than locations, allowing formerly secret grand jury testimony to be used to warn of impending attacks, new electronic and online eavesdropping ability and the authorization to detain non-citizens without much oversight.
The Bush administration -- notably Attorney General John Ashcroft -- requested these new powers, which were offset by a four-year sunset that forces Congress to review and re-approve the new powers.
The Bush request and the original Senate version did not have such a provision, but it was added at the insistence of the House.
The Senate added provisions that bolster federal law enforcement's ability to monitor and prevent money laundering by terror organizations.
Despite complaints from Feingold and some civil liberty groups that the bill goes too far in curbing constitutional rights to privacy, Senate Majority Leader Tom Daschle, D-S.D., said that it actually protected rights, while increasing security.
"This legislation balances civil liberties and privacy with the needs of law enforcement to fight terror," Daschle said.
Minority Leader Trent Lott, R-Miss., repeated this view and said that bipartisan -- and bicameral -- cooperation helped pass a bill that he though might have been in some trouble.
"Three weeks ago this bill looked like it was hopelessly muddled," Lott said. "There has been some bipartisan courage here," Lott said.
"We do need to improve security, and we will do that," he said. "We did not want to say that we passed a bill, we wanted to make (the nation) more secure. And we did a heck of a lot better than just giving birth to a monster."
But Feingold disagreed, arguing that the Senate spent too little time on the merits of the bill, which he called a reaction to the terror attacks of Sept. 11 and one that hurt the nation's tradition of freedom.
"Some have said -- I think somewhat cavalierly -- that in these difficult times, we have to accept some reduction in our civil liberties in order to be secure," he said on the Senate floor shortly before the vote. "And, of course, there is no doubt that if we lived in a police state, it would be easier to catch terrorists."
But this would inevitably mean that the nation had lost the war on terrorism, he added.
"We will lose that war without firing a single shot if we sacrifice the liberties of the American people," he said.