WASHINGTON >> Donald McGahn, the former White House counsel, answered detailed questions from Congress behind closed doors today about President Donald Trump’s efforts to impede the Russia investigation. But McGahn provided few new revelations, according to people familiar with his testimony.

The fact that McGahn spoke to Congress at all was significant after a multiyear legal battle by the Trump Justice Department to block an April 2019 subpoena for his testimony. That dispute ended last month, when President Joe Biden’s Justice Department, House Democrats and a lawyer for McGahn reached a compromise under which he finally showed up.

Still, the interview by the House Judiciary Committee, attended by only a half dozen or so lawmakers on a summer today when Congress was on recess, was an anticlimactic conclusion to a saga that once dominated Capitol Hill. When Democrats first subpoenaed McGahn, they believed his testimony under oath and on live television could help build public support for impeaching Trump for obstruction of justice and other matters.

Instead, in the time it took to sort out a tangled legal battle, questions about the events McGahn witnessed have largely faded into the background or been carefully detailed by the special counsel, Robert Mueller. Trump’s presidency turned up newer issues for which the House impeached him twice — and the Senate acquitted him both times.

“I believe we have been vindicated in terms of the intimacy of his involvement and the ultimate conclusions of the Mueller report,” Rep. Sheila Jackson Lee, D-Texas, told reporters as she exited the session. “The Congress has to be respected with its subpoena and oversight responsibilities.

“Today, we asserted that right,” she added.

But under the strict limits imposed by the terms of the deal, McGahn’s appearance broke little new ground, according to those familiar with it, who spoke on the condition of anonymity because they were not authorized to discuss it. The agreement limited questioning to matters that were described in the publicly available portions of Mueller’s report.

McGahn will have up to a week to review a transcript for accuracy before it is made public. But the people said that he hewed closely to the account he had already given the special counsel, often telling committee lawyers that his recollections of events from four years ago were no longer sharp.

Republicans were pleased to declare the interview a waste of time as they left the session after more than five hours of questioning.

“Today, we have the House Democrats on the Judiciary Committee relitigating the Mueller report,” said Rep. Jim Jordan of Ohio, the top Republican on the Judiciary Committee. “Don McGahn hasn’t been White House counsel for three years.”

McGahn was a witness to many episodes described in the second volume of the Mueller report, which centered on potential obstruction of justice issues; his name appears there more than 500 times.

In June 2017, for example, Trump called McGahn at home and ordered him to tell Rod Rosenstein, the deputy attorney general, to fire Mueller over a dubious claim that the special counsel had a conflict of interest. McGahn refused and was prepared to resign before Trump backed off, according to the Mueller report.

After the report became public, Trump claimed on Twitter that he had never told McGahn to fire Mueller. Two people familiar with the hearing today said that the session had spent a lengthy period going over that episode, and that McGahn had testified under oath that the account in Mueller’s report was accurate.

The report also described a related episode that followed a January 2018 report by The New York Times that first brought to public light Trump’s failed attempt to have Mueller fired. Trump tried to bully McGahn into creating “a record stating he had not been ordered to have the special counsel removed” while also shaming the lawyer for taking notes about their conversations. But McGahn refused to write the memo.

McGahn was also a major witness to several other episodes recounted in the obstruction volume of Mueller’s report, including the White House’s handling of the Justice Department’s concerns that Trump’s first national security adviser, Michael Flynn, was vulnerable to blackmail by Russia over false statements he had made about his conversations with the country’s ambassador. McGahn was also part of deliberations leading to Trump’s firing of James Comey, the FBI director.

Democrats were eager to claim McGahn’s testimony on Friday as a victory despite the lack of new disclosures, saying it upheld the principle that a White House could not prevent a key administration official from testifying before Congress. It added a second precedent to one created in 2009, when the new administration of President Barack Obama struck a deal to end litigation he had inherited over whether President George W. Bush’s former White House counsel, Harriet Miers, would testify about firings of U.S. attorneys.

But because the compromise agreement to permit McGahn to testify effectively cut short the litigation, a federal appeals court never issued any binding precedent to resolve the long-running ambiguity over whether Congress can sue the executive branch in a subpoena dispute. That means the next time such a clash arises, Biden or a future president can again stonewall Congress and litigate the same issue all over again.