American Airlines said its operations returned to normal on Wednesday after it canceled nearly 1,000 flights on Tuesday because of a computer outage.
The airline also said it halted about 100 flights on Wednesday to reposition crews and planes, and because of bad weather in the Chicago area.
At Dallas Fort Worth International Airport (DFW), American's biggest hub, the carrier canceled 37 fights for Wednesday but was operating on schedule, spokesman David Magana said.
"We had about 1,500 passengers who opted to stay overnight inside DFW Airport terminals, but today the passenger check-in lines have subsided," he added.
On Tuesday, American grounded its U.S. flights for several hours because of intermittent computer outages. The carrier canceled 978 flights, and hundreds more were delayed. American said a software issue that affected its primary and backup network systems caused the problem.
The carrier said in a statement on Wednesday it added extra flights to help customers whose travel plans were disrupted by the outage. The extra service included flights between Chicago's O'Hare airport and DFW, Los Angeles and DFW, and Los Angeles and Miami.
American, a unit of AMR Corp, which plans to merge with US Airways Group this year, said it had no evidence that the issues were related to bombings in Boston on Monday. The carrier operates more than 3,500 daily flights worldwide.