Mr. Obama will become the first U.S. President to make such an appeal to the International Olympic Committee.
In just four days the IOC will reveal which of the four bid cities will host the 2016 Summer Games.
The plane took off on Monday evening. Many people on the plane have worked on the Olympic bid since the very beginning. The pilot told them that the call assigned for the flight is Chicago 2016. Joining them onboard were some of the country's best known Olympians.
The 200 or so in the group traveling to support the city's Olympic bid got a Chicago-style sendoff complete with music from the Blues Brothers. The mood was upbeat.
"I'm excited. This is very important to me. I'm a Chicagoan," said former Olympian boxer David Diaz.
The group includes a number of former Olympians like Diaz who is from Chicago and some of the greatest Olympians ever including Jackie Joyner-Kersee.
"You never want to go into a competition overconfident," said Jackie Joyner-Kersee, former Olympic track & field athlete.
The athletes went along to try to influence IOC voters. Many say they are almost as nervous as if they were competing. They feel confident in the chances but anything can happen with the historically unpredictable IOC.
"The bid could win on its own merit. There are four fabulous cities all competing. It is going to be very, very close," said Bart Conner, former Olympic gymnast.
The group is traveling in style a 747 from United Airlines. They hoped to come back with what they believe is a big gift to the city - the right to host the 2016 Games.
"We depart now for Copenhagen looking forward to the exciting opportunities that await the future of our city," said Maggie Daley.
The planes is scheduled to arrives in Copenhagen around 1 p.m. on Tuesday. They have a number of activities planned. Another team has been on the ground in Copenhagen for several days.
The IOC will make its decision next Friday, October 2.
ABC7 will provide complete coverage of the announcement. A timeline of coverage can be found here. Ben Bradley will report live from Copenhagen starting Tuesday.
On October 2nd, the host city winner announcement is expected at about 11:30 a.m.
All of events will also be streamed live on our Web site, abc7chicago.com.