U.S. dockworkers agreed to return to work after port operators sweetened their contract offer, ending a three-day strike that threatened to disrupt the American economy. The breakthrough Thursday came after port employers offered a 62% increase in wages over six years,

The union representing U.S. dockworkers has signaled that 45,000 members will walk off the job at midnight, kicking off a massive strike likely to shut down ports across the East and Gulf coasts.