The U.S. law that is the foundation for opening the government's filing cabinets to its citizens has provoked bureaucratic headaches since President Johnson begrudgingly signed it 40 years ago Tuesday — and he worried immediately that it might force the disclosure of damaging national secrets, newly disclosed records show.

Decades later, the Freedom of Information Act still regularly creates tension between the government and citizens, corporations, researchers and journalists. The law's staunchest advocates believe its principles have never been so imperiled, threatened by what they describe as the Bush administration's penchant for secrecy and concerns about revealing strategies to terrorists.

"This is the worst of times for the Freedom of Information Act in many ways," said Paul K. McMasters of the First Amendment Center, which studies issues of free speech, press and religion. McMasters cited large backlogs of unresolved citizen requests for records, and new Bush administration strategies to withhold documents.

In 1966, President Johnson was so uneasy about the new legislation he refused to conduct a public signing ceremony that would draw attention to it. He also submitted a signing statement that some researchers believe was intended to undercut the bill's purpose of forcing government to disclose records except in narrow cases.

Draft language from Johnson's statement arguing that "democracy works best when the people know what their government is doing," was changed with a handwritten scrawl to read: "Democracy works best when the people have all the info that the security of the nation will permit."

This sentence was eliminated entirely with the same handwritten markings: "Government officials should not be able to pull curtains of secrecy around decisions which can be revealed without injury to the public interest." Another scratched sentence said the decisions, policies and mistakes of public officials "are always subjected to the scrutiny and judgment of the people."

The 1966 papers were discovered in the Lyndon Baines Johnson Library and Museum in Austin, Texas, by the National Security Archive at George Washington University. The group's researchers make more than 1,500 requests for government records under the Freedom of Information Act every year on U.S. national security and foreign policy.

The archive's director, Thomas Blanton, said it was unclear from the documents whether Johnson personally edited his statement or directed his press secretary, Bill Moyers, to make changes. Moyers, who later became a prominent PBS journalist and frequent critic of conservatives, has recounted Johnson's unease about signing the new information law in 1966.

Tension over the law continues. Seeking records can be a hair-pulling experience, with requests often taking months or even years before paperwork — if any — is returned, and the government is under orders to improve its system.

"The Freedom of Information Act is embattled and at risk," said Meredith Fuchs, the top lawyer at the security archive. "The federal government is really shutting down the taps on information."

But when President Bush instructed agencies to review their information programs, many of them — including the CIA and Pentagon — boasted about their performance. The Justice Department said its handling of FOIA requests for records was working "exceptionally well," although officials acknowledged there was "room for improvement."

The CIA, famously loath to open even its historical files, cited its "strong record" on disclosures. The Pentagon — where records requests can languish for over a year — said its "customer responsiveness is generally good." The Homeland Security Department and State Department did not complete the mandatory reviews ordered by Bush.

Brian Martin of Denver, a private computer-security consultant, submitted two requests for records to the Homeland Security Department more than a year ago — and never heard back. Martin sought information about how much the government spends tracking software problems exploited by hackers and others.

"This process is supposedly there to get me information about how my tax dollars are being spent," Martin said. "I'm curious how it's all being used. I'm left just to wonder." When he sent a similar request to the Commerce Department, it told him he could have the records he wanted — if he would pay more than $1,800 for copying and search fees.