The security queue at Chicago's Midway International Airport reached more than a mile long on Sunday morning following Thanksgiving celebrations.
Tens of thousands of passengers queued for hours to return home from Thanksgiving trips with many travelers missing flights, Fox 31 Denver reports.
The line stretched the entire way through the airport terminal and doubled back on itself.
The Transportation Security Agency said that wait times returned to normal by 10a.m.
A spokesman for the Chicago Aviation Department said: "This happens sometimes. There was a period of time earlier this morning, between 6 a.m. and 8 a.m., that lines were long because that is when most people are traveling for the holiday period."
Nationwide, more than 2.5 million people were expected to fly on Sunday.
According to the Daily Mail, 3,000 flights were delayed and 190 canceled across the country.
Woman dies at airport after security scanner caused pacemaker malfunction
Airport security 'spills woman's ashes into grieving son's luggage'
Nobel Prize winner questioned by airport security over award
Drunk gets through Birmingham Airport security and boards empty plane