President Obama's attendance at the First Four is the first campus visit by a sitting president, though Bush, Carter and Ford also made appearances.

When President Barack Obama brings British Prime Minister David Cameron to tonight's the First Four of the NCAA Division 1 Men's Basketball Championship at the University of Dayton Arena, it will mark the first time a U.S. president has visited campus while in office, according to the University of Dayton archives.

As a candidate, George W. Bush came to campus on July 31, 2000, for a rally in the Humanities Plaza. Former President Jimmy Carter headlined the 1992-93 Distinguished Speakers Series at the University of Dayton Arena on Sept. 14, 1992.  Former President Gerald Ford keynoted the bicentennial of the signing of the U.S. Constitution at the University of Dayton Arena on Sept. 16, 1986.

"This is a great honor and a history-making moment for the University of Dayton Arena and the Dayton community," said Tim O'Connell, the University's senior associate athletics director. "The presence of the president and the prime minister along with the competitive tradition of this great American sports event guarantee an unprecedented level of excitement and a night to be remembered."

CBS Sports basketball analyst Clark Kellogg is expected to conduct a live interview with Obama and Cameron at half time on TruTV, which is airing the opening game between Mississippi Valley State and Western Kentucky University.

Ohio Gov. John Kasich also plans to attend the opening game Tuesday night and is expected to greet the leaders upon their arrival.

The opening night crowd will include 20 University of Dayton students, who will sit near the president and prime minister, and 500 family members of Wright-Patterson Air Force base personnel serving overseas.

A local organizing committee — a coalition of community, business, Air Force and higher education leaders — is branding Dayton as the place where March Madness starts. In concert with the NCAA and with the help of 300 volunteers, they staged a huge street party along several blocks in the city's cobblestoned Oregon Historic District on Selection Sunday. The all-day, family-friendly festival drew more than 15,000 people, according to regional leaders. CBS Sports gave the festival national exposure in a story featuring the University of Dayton pep band during its Selection Sunday coverage.

In all, the First Four Festival and March 13-14 games are expected to pump at least $4 million into the local economy, according to the Dayton-Montgomery County Convention and Visitors Bureau.

That's on top of the national visibility the University of Dayton and the region will garner. When the University hosted the inaugural First Four games last March, the campus was mentioned nearly 1,000 times in the nation's top 100 media markets. That also includes media attention for faculty experts and University programs in high-profile publications like The New York Times, Bloomberg Radio, USA Today and CNNMoney.com, but the coverage quadrupled over an average month. In all, the audience reached 2.8 billion, with an advertising value of $1.2 million, according to data compiled by Cision, a media-tracking service.

"No Matter Who's in the Tournament, Dayton Takes the Lead," reads the headline on a full-page ad in U.S. Airways magazine this month (Click here to download the ad or view the gallery on the right). A digital billboard outside downtown Dayton welcomes the president and prime minister.

The NCAA has issued 185 press passes for the two-day tournament. The BBC, CNN, Associated Press, Gannett, Bloomberg, ESPN.com, CBSSports.com, ESPN.com, Sporting News and the New York Post are among the media expected to cover the event. In addition, the White House press corps will travel with the president and prime minister.

With the British prime minister in the stands, the First Four this year should receive an unusual amount of international attention. And it's about hoops.

"What's March Madness all about?" a reporter from The Times of London asked the University communications office.