The Rivers Casino created 1,000 jobs and is expected to bring in tens of millions of dollars for the State of Illinois.
This comes after years of legal and regulatory fights over its gambling license.
On the first day, the most immediate impact was traffic. At one point, casino officials asked people to consider coming back another day, as capacity was reached shortly after opening. By late afternoon, the lines had died down, and patrons were welcomed inside without waiting.
Surrounding businesses are wondering what long-term impact the casino -- and its guests -- might have. Rivers Casino has spawned more than 1,000 new jobs for people like 79-year-old Chicagoan Joanne Abbamonto, who works on the security staff.
"Financially, it's going to make a big difference in my own personal life and finances. I got caught in that '80s crash," said Abbamonto.
More than employment, the casino is anticipated to generate $150 million tax dollars for the state each year.
"The funds going back to the state, and the states are very knowledgeable about what they do with the money. So I'm sure it's going to supports a lot of the projects for the state," said Bill Keena, Rivers Casino, general manager.
Nearby businesses are looking for a boost too.
"People will stop in before they go gamble and I think we'll benefit from it," said Vicky Stavrou, of Mrs. V's restaurant.
"Anything that provides economic development in the long run is good for everyone," said James Macchiaroli, of ACE Des Plaines. "It's good for the community. It's good for all the local businesses. I don't think we're gonna see a change overnight, but I think long-term it will be a good building block for economic development and growth."
But the new facility could draw gamblers from other venues like Arlington Park race track in Arlington Heights and the Grand Victoria Casino in Elgin.
The mayor of Elgin says the casino used to bring in $24 million a year for the city's senior rebate program, road resurfacing and new construction. With the opening of the new casino, they are only expecting $10 million for Elgin this year.
"It's going to be tough for all of us," said Elgin Mayor David Kaptain. "I think that Elgin in particular might be the hardest hit of all the communities in the state."
Kaptain said he will work with Grand Victoria to see what they can do to bring in patrons.
Arlington Park Racetrack's general manager said every time a new casino opens they see a dip in attendance. He said he expects to see that with the opening of the Rivers Casino.