As he crisscrosses the country on the campaign trail, Democratic presidential hopeful Barack Obama is filling up arenas and halls like no candidate in recent history. In February, campaign stops in Minneapolis; Hartford, Conn.; Seattle; and Virginia Beach, Va., among others, each drew between 15,000 and 20,000 attendees.

Often these massive events materialize just days before they're to happen, setting off a flurry of last-minute activity. If you've ever wondered how it all comes together, Courtney Dyer, general manager of the Virginia Beach Convention Center, has a story to tell:

“We were coming out of the American Bus Association convention, and on the final day, Thursday, I got a call around lunchtime from one of the advance people from the Obama campaign. She wanted to know about availability,” Dyer explains. They wanted to hold a rally at the Virginia Beach Convention Center on Sunday, February 17, just three days after the close of the ABA convention and only a few days before the next event.

“It was kind of a fluke that we had a little window between American Bus and a big home show we were moving in,” says Dyer. “We had already fried our staff on the [bus] convention, which was a pretty big event for us, but we were up for the challenge.”

Dyer was surprised they sought out the convention center because in other cities Obama had used arenas, which are probably better suited for 20,000-person rallies than wide open exhibit halls without seats or bleachers. “We aren't really designed for that kind of thing — large assemblies of people in a standing crowd,” she says. But after flying to Virginia Beach from Chicago to meet with Dyer on Friday, the Obama planners settled on the convention center for the Sunday campaign stop. By Friday afternoon, the contract was signed and the down payment was set — it was a go. Then, says Dyer, “we started planning in earnest.”

They got to work setting up a 16-foot-by-16-foot stage in the corner of the 150,000-square-foot exhibit hall, where the Illinois senator and presidential hopeful would make his speech. Two large press platforms, rigged to supply power and big enough for cameras and audiovisual equipment, were built on two sides of the stage for the 100 or so members of the local and national media who would cover the event. The Obama staff contracted out for AV services but surprised Dyer by not using big-screen monitors.

Behind the stage, the convention center staff rigged a large American flag. Obama staffers wanted bleachers set up behind the stage so that the cameras would capture people behind the senator when he spoke, but the center didn't have the bleachers and it was impossible to get them on such short notice. They also asked for bike racks out front, which the center couldn't accommodate.

Because the rally was held on the exhibit floor, there were no seats. The 15,000 to 18,000 people who packed the hall on Sunday were all standing, except for those who needed special assistance. When Obama's advance team had told him to expect at least 15,000 people, Dyer had been skeptical. After all, Obama's team hadn't spent a nickel on advertising, and just three days earlier, no one knew that the event would be there.

As it turned out, a press release sent out on Friday or Saturday announcing the location of the Sunday rally was all it took to attract the crowd. People started lining up outside the building early Sunday morning. Dyer says it was probably the largest crowd in the exhibit hall for a single event since the convention center opened two years ago.

Inside the building, the Obama team arranged security, while local law enforcement patrolled outside and handled crowd control and traffic. Security scanners set up at the entrance were provided and administered by the Transportation Security Administration. Crowds were well-behaved and there were no incidents, Dyer says.

The speech, of course, got national attention, plastered across newspapers and beamed to television screens all over the world. It was great exposure for the convention center. And, yes, Obama won the Virginia primary just two days after the rally.