CHICAGO — Chicago began its pitch to host the 2016 Summer Olympics in earnest today with a message from the city's most famous part-time resident: President Barack Obama.

In a four-minute video that was shown to shown to the International Olympic Committee inspection team, Obama touched on themes that organizers will stress throughout the IOC visit, starting with a reminder that Chicago is a global city and home to people from all over the world.

"It's a city where races, religions and nationalities all live and work and play and reach for the American dream that brought them here," said Obama, who moved to Chicago as an adult.

Obama talked about classrooms "filled with the sounds of the world's languages," and all kinds of music.

One of the biggest questions the IOC faces is what city can be counted on the most to be able to build an Olympic Village and all the venues during a worldwide recession. And as Chicago 2016 organizers have done, Obama reminded the IOC of the city's history that includes rebuilding after the Great Fire of 1871 and hosting its second World's Fair during the height of the Great Depression.

"This is a city that lives and breathes the ideals of perseverance," he said.

After reminding the IOC that Chicago is the birthplace of the skyscraper, the president also portrayed Chicago as a forward-looking "city that Mayor (Richard) Daley has pledged to make the greenest in America."

Daley has called Obama the "quarterback" of the city's effort to secure the games and his election in November was seen as a boost for Chicago as it competes with Madrid, Rio de Janeiro and Tokyo for the games. Although other cities downplayed the affect of Obama's election, Spanish Sports Minister Jaime Lissavetsky has acknowledged that he would have rather seen the unpopular George Bush in the White House when the IOC makes its decision in October.

For his part, Obama made his connection to the city that he moved to as an adult, worked as a community activist, law school professor and launched his own political career as part of his pitch.

"After your visit, once you discover the Chicago that I know — the city that I made my home, the city where my wife grew up, the city where we raised our daughters just blocks from where these games will be held — I am confident you will discover that you're already in the perfect host city..."

On Saturday, Chicago 2016 was opening its presentation with its vision for the games, with themes such as friendship and peace.

The IOC will also hear about the venues, with Chicago 2016 organizers stressing how close many of the venues are to each other and cultural attractions such as the Field Museum and the Art Institute of Chicago.

On Sunday, the IOC will be given a tour of the various venue sites.