But even if the Teamsters' fight marks a turning point, the labor movement has a long way to go to reclaim its former social and political clout. And a federal grand jury is pressing an inquiry into Carey's re-election fund-raising.
"This strike marks a new era," Carey proclaimed after sealing this week's deal to end the most successful labor action in more than a decade. "This strike sends a signal that American workers are on the move again."
Unions represent about 10 percent of the private work force _ a far cry from labor's peak after World War II, when 35 percent of American workers belonged to a union.
AFL-CIO President John Sweeney, who vowed to use the Teamsters victory to "renew the fight for good jobs," has warned that unions could become irrelevant unless they bolster their ranks. By some estimates, labor needs to enlist more than 200,000 new members a year just to maintain its market share.
"It's far too early to tell whether this is a watershed; it's clearly a change in direction," former Labor Secretary Robert Reich said after the UPS settlement. "Whether this signals a resurgence of organized labor depends on what happens from here on."
That's the challenge Sweeney faces as he stands unopposed for re-election to lead the 13-million-member labor federation next month.
Sweeney and leaders of several large unions seized the reins of the AFL-CIO two years ago, promising to be a stronger advocate for workers and to aggressively recruit new union members.
Under Sweeney, the AFL-CIO has raised its public profile and mounted an aggressive media campaign to force candidates in the 1996 congressional races to address workers' issues.
But there hasn't been dramatic growth in union rolls, and his supporters say they didn't expect a quick turnaround given the long years of decline.
"I think it's unfair to judge it simply on numbers. It's really a test over time," said Andy Stern, president of the Service Employees International Union. "The fact that we're back and we're relevant to the American discourse, and that we've upgraded our organizing and political and public relations efforts, sows the seeds for long-term positive growth."
Some economists say the changing marketplace still will force more companies to rely on low-wage, part-time workers, which will continue to depress labor's membership numbers.
But skyrocketing corporate profits, the fact that workers haven't shared equally in a booming economy, a tight labor market and a more aggressive labor movement make what Reich called a "combustible combination."
"Put all that together and this UPS settlement may be just the start of a reversal of the fortunes of blue-collar America," he said.
It certainly seemed like a reversal of fortune for Carey.
He was hailed as a reformer when he first took over the union in 1992, but Carey's time behind the wheel of the International Brotherhood of Teamsters has been a rough haul.
His opponents accused him of being a weak leader, of consorting with mob figures and even of bilking an elderly woman out of her life savings. Carey replaced the leaders of 72 corrupt local unions and eliminated double salaries for Teamsters officers.
But his 1996 re-election campaign is under scrutiny by a federal grand jury in New York after a campaign consultant was charged in schemes to funnel union money and other prohibited funds into Carey's campaign. Carey himself has not been accused of wrongdoing.
The union's ties to the Democratic National Committee also caught the grand jury's attention, and the party and union were subpoenaed last month. William Hamilton, the union's political director, has resigned.
Carey won re-election by less than 4 percent of the vote and his challenger, James P. Hoffa, has urged federal overseers to call for a new vote. A decision is expected soon.
If UPS was counting on such divisions to widen during the strike, it miscalculated, said labor scholar Michael Belzer.
"I think the union comes out of this stronger than ever," Belzer said.