While an effort to reform the nation's open records law failed to gain much traction in 2015 after a promising start, the Freedom of Information Act still quietly shaped much of the year's political landscape.

Reporters and transparency advocates used FOIA to unearth documents related to FBI surveillance, CIA spying on Congress and the State Department's handling of the 2012 Benghazi attack.

But the most high-profile FOIA victory came in the form of a lawsuit filed by Jason Leopold, a reporter at Vice News, who in May forced the State Department to begin releasing all 55,000 pages of Hillary Clinton's private emails at the end of every month until January 2016.

"The fact that it was released based on a judge's order to the State Department to release those emails, certainly put FOIA on the map, in a way, just this year," Leopold told the Washington Examiner.

"I'm not trying to suggest that it was unknown, but it really sort of raised awareness of how powerful, in my opinion, the FOIA is," he added.

The prolific FOIA user, who was dubbed the "FOIA terrorist" by government officials fed up with his frequent filing, said the Clinton email controversy drew attention to the difficulty journalists and watchdog groups routinely face when they attempt to force the release of records through FOIA.

"It wasn't just my lawsuit ... that shined a light on these abuses, it was actually FOIA requests that were filed by the Associated Press, by Judicial Watch, by Gawker, to the State Department for communications about Hillary Clinton that really raised awareness about the stonewalling that goes on regularly within government agencies when it comes to trying to force the government to be transparent," he said.

Leopold's FOIA lawsuit posed problems for the Clinton campaign by forcing the former secretary of state to confront on a monthly basis questions about her use of a private email server to shield her communications from the public.

Tom Fitton, president of Judicial Watch, said the success of lawsuits related to Clinton's email records proves FOIA is the most effective tool for exposing the government.

"It shows you that the Freedom of Information Act ... has done a better job of policing and holding accountable some of the most powerful people in the world than all of Congress and the big institutional media," Fitton said.

His conservative watchdog group filed 384 federal FOIA requests this year and sued the government over 44 requests that went unanswered in 2015.

Among Judicial Watch's biggest wins was an August order forcing Clinton to affirm under penalty of perjury that she handed over all of her work-related emails — a declaration that could take on new significance in light of an open FBI investigation into her email use.

At the end of last year, the State Department had a backlog of 10,041 records requests. The agency has not yet released its annual FOIA report for 2015, but officials have complained in multiple court filings about the spike in requests stemming from the Clinton email controversy.

The more than 100 percent increase in FOIA requests to the State Department this year will undoubtedly enlarge the agency's backlog of unanswered requests.

However, the State Department is far from the only agency to leave hundreds or even thousands of FOIA requests collecting dust as the year draws to a close. Those include several filed by the Examiner.

For example, the attorney general's office processed fewer FOIA requests this year than it had pending at the end of last year. In other words, it did not make enough progress on the leftover FOIA requests from 2014 to get to the new ones filed this year.

Other agencies denied far more requests than they granted. The Bureau of Alcohol, Tobacco and Firearms fully denied more than twice the number of FOIA requests they granted this year.

David Bossie, president of Citizens United, pointed to the fact that litigation was required to make the Clinton email FOIA requests effective as evidence that the open records law needs reform.

"Without Citizens United and other organizations using the Freedom of Information Act, the American people would not know a lot of what they know about Hillary Clinton's intertwining of State Department and Clinton Foundation business," Bossie said. "And only through litigating did the American people get that information."

Bossie said the implementation of the law should be changed so everyone, not just individuals or groups with the resources to sue, can use FOIA to get the records they want.

"Through our winning these cases one after the other after the other, we are proven correct, that the American people did have the right to the material," Bossie said of the dozens of lawsuits filed by Citizens United and other transparency groups this year.

Citizens United used FOIA to uncover documents linking key Clinton aides to Clinton Foundation operations, including an email showing a State Department staffer passing now-classified intelligence to a foundation employee.