Looking back at 7 of history’s most notable Congressional hearings and testimonies

— -- All eyes in Washington, D.C., will be on former FBI Director James Comey as he testifies today in front of the Senate Intelligence Committee, which is investigating Russia's alleged interference in the 2016 election.

While the highly anticipated testimony from Comey could well become one of the more notable hearings in congressional history, here are some of the other contenders for the most high-profile legislative testimonies and hearings from the past.

Hillary Clinton - 2013 Benghazi hearing

On January 23, 2013, Hillary Clinton was grilled about the 2012 attack on the U.S. consulate in Benghazi, Libya, that left U.S. ambassador Christopher Stevens and three other Americans dead.

"With all due respect, we had four dead Americans. Was it because of a protest or was it because of guys out for a walk who decided they'd go kill Americans," Clinton said that morning before the Senate Foreign Relations Committee.

Clinton was referring to former national security adviser Susan Rice's comments on "Meet the Press" that the attack was the result of a protest against a video made in the U.S., not a planned terrorist attack.

"What difference at this point does it make? It is our job to figure out what happened," Clinton said.

Clinton returned to testify for a second time on Capitol Hill in 2015 when she was a candidate for president -- this time in front of the House Select Committee on Benghazi.

John Dean and Alexander Butterfield - 1973 Watergate hearings

The Senate Select Committee on Presidential Campaign Activities -- known colloquially as the Watergate Committee -- began holding hearings in 1973 to investigate "illegal, improper, or unethical activities" related to the 1972 presidential race between Richard Nixon and George McGovern.

The investigation was launched after a break-in at the Democratic National Committee's Headquarters at the Watergate hotel was connected to Nixon campaign aides.

Among the notable testimonies from the hearings was that of former White House counsel John Dean, who testified that President Nixon himself knew about the cover-up of the burglary at the DNC's headquarters.

On June 28, 1973, ranking minority member Howard Baker famously asked, "What did the president know and when did he know it?"

On July 16, 1973, Nixon's aide Alexander Butterfield revealed that Nixon recorded tapes in the Oval Office of his conversations, leading to the tapes being subpoenaed. Those tapes later revealed an 18.5-minute gap that the White House couldn't explain.

The end result of the hearings was incredibly influential -- it ultimately resulted in a president's resignation for the first and only time in American history.

Sally Yates - 2017 Russia investigation hearing

Another high profile testimony this year was former acting-Attorney General Sally Yates, who had been fired by President Trump over his travel ban.

Yates testified that she had informed Don McGahn, the White House counsel, that the administration had been misled by then-national security adviser Mike Flynn about the nature of his calls with U.S. ambassador Sergey Kislyak.

Yates also said she had warned McGahn that the Justice Department believed the Russians had compromising information on Flynn, which they could potentially use to blackmail him.

"We believed Gen. Flynn was compromised in regards to the Russians," Yates told the Senate Judiciary Committee in a hearing on May 8.

"Mr. McGahn asked me... why does it matter to DOJ if one White House official lies to another White House official?" Yates said. "To state the obvious, you don't want your national security adviser compromised with the Russians."

Lt. Col. Oliver North - 1987 Iran-Contra hearing

The second term of the Reagan administration was punctuated by the Iran-Contra affair, a political scandal that revealed that the White House secretly facilitated the sale of weapons to Iran, which was at the time was under an arms embargo.

The administration secretly struck a deal with Iran to sell them weapons in exchange for Iranian efforts to release seven Americans who were being held hostage by the Iranian-allied paramilitary group Hezbollah in Lebanon.

Meanwhile, in Nicaragua, a right-wing insurgent group called the Contras were battling the Sandinistas, a socialist group that ruled the country. Reagan's preferred method for eradicating communism around the world in this case butted heads with congressional Democrats, who had passed the Boland Amendment, which specifically restricted the administration's efforts to aid the Contras in Nicaragua.

The congressional investigation into Reagan's arms-for-hostages deal found that only a portion of the funds the Iranians paid had reached the U.S. government.

In July 1987, Lt. Col. Oliver North said, "I came here to tell you the truth -- the good, the bad and the ugly." He eventually revealed that he diverted funds from the Iran deal to the Contras in Nicaragua and claimed President Reagan was aware of his activities.

Lloyd Blankfein - 2010 Financial crisis hearing

A two-year-long congressional investigation into the causes of the 2008 financial crisis examined the devastating recession resulting from a crisis in the nation's housing mortgage industry.

One of the most notable testimonies of the investigation was that of Lloyd Blankfein, the chairman and chief executive officer of Goldman Sachs.

Then-Sen. Carl Levin asked Blankfein, in reference to risky mortgages sold by his bank, "Is there not a conflict when you sell something to somebody, and then are determined to bet against that same security, and you don't disclose that to the person you're selling it?"

"In the context of market-making, that is not a conflict," Blankfein replied.

The result of the Senate's investigation was a 650-page report entitled, "Wall Street and the Financial Crisis: Anatomy of a Financial Collapse," which detailed the deceptive practices of the nation's largest mortgage lenders.

1954 Army-McCarthy Hearings

During the peak of the Red Scare, when Americans worried about the spread of world communism, Wisconsin Sen. Joseph McCarthy heightened people's fears with his allegations that hundreds of Communists had infiltrated the State Department.

Using his platform as chairman of the Senate Permanent Subcommittee on Investigations, McCarthy conducted several hearings hoping to purge the federal government of alleged Communists and Soviet spies.

McCarthy then turned his accusations toward the Army, where he conducted nationally-televised hearings lasting from April until June of 1954.

On June 9, 1954, during one of the sessions, a dramatic moment occurred between McCarthy and Joseph Welch, the lawyer representing the Army in the hearings. McCarthy accused one of Welch's attorneys of harboring ties to a Communist organization.

"Until this moment, Senator, I think I never really gauged your cruelty or your recklessness," Welch shot back, defending his employee. "Let us not assassinate this lad further, senator. You have done enough."

McCarthy attempted to continue his accusations and Welch exclaimed, "Have you no sense of decency?"

The hearings irreparably damage McCarthy's credibility and, once the hearings were over, McCarthy's fellow Senate colleagues voted to censure him.

Anita Hill - 1991 Clarence Thomas confirmation hearing

Attorney Anita Hill became a national figure when she testified on Capitol Hill in 1991, alleging her former boss Clarence Thomas, who had been nominated to the U.S. Supreme Court, had sexually harassed her over the years she worked with him.

"My working relationship became even more strained when Judge Thomas began to use work situations to discuss sex," Hill testified, later adding, “After a brief discussion of work, he would turn the conversation to a discussion of sexual matters. His conversations were very vivid."

Hill had worked for Thomas at the Department of Education and Equal Employment Opportunity Commission.

During those three days of Thomas' confirmation hearings in October 1991, Hill also alleged that while she was working as his assistant, Thomas used crude language and talked about pornography around her, and repeatedly asked her out though she declined.

Thomas maintained his innocence and said he was hurt by Hill's allegations.

"I have not done what she has alleged, and I still do not know what I could possibly have done to cause her to make these allegations," Thomas said in his testimony.

Despite the allegations by Hill, Thomas was confirmed by the Senate in a narrow vote, 52-48.