Parts of Michigan, Ohio and Massachusetts also got more than a foot of snow.
Local responders as well as National Guard members were helping Midwesterners dig out from the storm's damage.
"This storm is still moving, it's still going to affect the Northeast," Federal Emergency Management Agency administrator Craig Fugate said. "The biggest problem right now is transportation ... with the airports being closed, interstates. And overnight, a lot of people were stranded."
Amtrak service in the Midwest and Northeast was curtailed. Several trains scheduled to depart from Chicago were canceled. Trains were operating on a delayed schedule in some parts of the Northeast.
Across the nation, 5,634 flights had been canceled as of 12:20 p.m. ET, according to Flightaware. The total number of flights canceled this week swelled to 13,608 flights.
Chicago's O'Hare Airport, perhaps the hardest hit, was closed today after 20.2 inches of snow fell in the city and high winds created blizzard conditions. Chicago's public schools were closed for the first time in 12 years.
With final numbers still to come, it was the third-largest storm on record in Chicago, beating the infamous storm of 1979 that left 18.8 inches and was widely considered a factor in the city's mayoral race.
Monday night, thunder snow and lightening shocked Chicago residents. Winds as high as 60 miles per hour created whiteout conditions, limiting visibility and halting traffic.
Lake Shore Drive was shut down after commuters were trapped in standstill traffic for up to 12 hours Monday. A cascading series of car and bus accidents within a 15-minute period Monday night forced the highway's closure. Up to 900 cars were stuck in snow so deep they could not escape. Overnight, firefighters traveled by snowmobiles to help drivers push their cars to safety.
Jaco Collins spent most of the night trapped in his truck.
"The guy behind me here got stuck and pinned me," Collins said. "I was inside ... for almost seven hours."
Illinois officials deployed as many as 700 members of the National Guard to help stranded motorists. Some of the stranded were taken to St. Joseph's Hospital. None of the people were hospitalized but many were soaking wet from the snow.
Stretches of the highway remain dotted with abandoned vehicles. Around the lake, winds are gusting at more than 60 miles per hour and there are snow drifts four feet high.
Even Chicago's iconic Wrigley Field was impacted by the storm -- with the press box of the 97-year-old ballpark sustaining damage.
More snow was expected throughout the day in Chicago. The area could see up to 24 inches of snow. The last major snowstorm there was in 1999, dumping about 19 inches. In 1967, 23 inches were dumped on the city.
Further west, a foot of snow crippled Oklahoma City. Stranded cars lined the ditches along the highways.
Tulsa, Okla., received record snowfall of 15 inches, according to the National Weather Service. The town's paper, the Tulsa World, was not printed this morning.
"This will be the first time in our history that we have not printed a Tulsa World," said publisher Robert E. Lorton III. "However, we wanted to make sure our employees and their families remained safe as we all try to deal with this weather."