This is part of the America's Future series airing on FOX News Channel, looking at the challenges facing the country in the 21st century.

CHICAGO — In an unassuming office in Des Moines, Iowa, law enforcement agents from state, federal, county and city agencies are all gathered under one roof in what has become a model of intelligence sharing.

Resources and databases are combined and critical crime-fighting information is shared, allowing law enforcement agencies big and small to be on the same page.

"We are safer and we are doing a better job but we are not yet safe and we have more work to do," said Russell Porter, director of the Iowa Intelligence Fusion Center.

Click here to see more on intelligence fusion centers.

Forty-eight states now have fusion centers based on an agency Iowa created in 1984. The idea has been refined to fill in gaps in intelligence-gathering that were discovered after the Sept. 11 attacks.

"The whole object is to change the investigative culture of what we do as a department, whether it's related to violent crime or Homeland Security, and we do a very good job of that," said Cdr. David Sobczyk of the Chicago Police Department. "Things that normally would have taken days, weeks or months to provide, we give instantaneously."

Chicago's fusion center is inside its police headquarters, where law enforcement agents not only help prevent terrorist attacks here at home, but share information in a global network.

According to Porter, the fusion center's network is connected to "open-source, suspicious activities that occur throughout the world, and this gives us a heads up if something happens in the Middle East, and we're able to link our intelligence to their intelligence."

Ben Stone, executive director of the American Civil Liberties Union in Iowa, says the ACLU isn't concerned by the overall mission of the fusion centers, but by how information is gathered and by a lack of political oversight.

"There's been a history in America of abuse — by the intelligence community, by the FBI — of American citizens' rights and their privacy," said Stone. "And we need to learn from history, not repeat it."

Stone says that intelligence-gathering should be conducted only overseas, and hopes that law enforcement officials won't collect information on innocent parties. "Just because you can do something, doesn't mean you should," he said.

Porter defended the fusion center, and said that maintaining security did not necessitate curtailing any rights. "There are those of us who think you don't have to throw the baby out with the bath water. Security, privacy and civil liberties can all be lifted up and held out as important."

But keeping America safe isn't cheap. There is a push from the federal government to force fusion centers to rely on funding from state and local Homeland Security grants. The problem, center directors argue, is that those local dollars carry restrictions on how they can be used.

Security experts say without proper intelligence-gathering, we run the risk of taking a step back in time to the days before 9/11, when critical information didn't reach the people who needed it the most.

Click here to see more reports on America's Future.