A subcommittee of the Senate Commerce Committee began these hearings on April 19, 1912, to investigate the causes behind the British ocean liner's disastrous sinking. According to the committee's report, more than 80 witnesses, including surviving passengers and crew, testified about the weather conditions and ice warnings, the collision and damage to the ship and the treatment and evacuation of the passengers.
The hearings lasted more than six weeks. The committee found that the accident indicated "the necessity of additional legislation to secure the safety of life at sea," according to the report.
The Army-McCarthy hearings
In 1953, as the new head of the Senate Permanent Subcommittee on Investigations, Sen. Joe McCarthy shifted its mission from investigating fraud to investigating Communism in the US. He called hundreds of witnesses to testify about potential Communist activity, according to Senate transcripts.
McCarthy launched an inquiry in April 1954 into alleged Communist infiltration of the US Army. The army countered that the Wisconsin senator had sought preferential treatment for a subcommittee consultant who had been drafted.
McCarthy stepped down as chairman and three months' worth of hearings followed, becoming a spectacle that was televised live across the United States. During a session in June, McCarthy alleged that one of the attorneys representing the army was tied to Communism.
It was in this exchange that the Army's lawyer, Joseph Welch, uttered the immortal line: "Have you no sense of decency?"
The Warren Commission hearings
President Lyndon B. Johnson established this commission a week following John F. Kennedy's death in 1963. Chaired by Supreme Court Chief Justice Earl Warren, the commission was tasked with investigating Kennedy's assassination and the killing of his alleged assassin, Lee Harvey Oswald.
The commission heard testimony from 552 witnesses, including Oswald's mother, brother and widow, according to the final report.
The hearings lasted nearly a year. The commission concluded that Oswald assassinated Kennedy, Jack Ruby killed Oswald, and that neither "was part of any conspiracy, domestic or foreign, to assassinate President Kennedy."
They were unable to determine a definitive motive for Oswald's actions.
The Watergate hearings
The Senate Watergate Committee was created in February 1973 following a unanimous Senate vote and was tasked with investigating the June 1972 break-in at the Watergate Hotel, its connection to President Richard Nixon's reelection campaign, and "all other illegal, improper, or unethical conduct occurring during the Presidential campaign of 1972, including political espionage and campaign finance practices," according to records.
The committee was chaired by Democratic Sen. Sam Ervin of North Carolina. The hearings, which opened in May 1973, dominated headlines and were broadcast nationally in prime-time coverage. The committee was granted the authority to subpoena for Nixon's infamous tapes -- an order with which he refused to comply. The Senate's public hearings concluded in February 1974. In July 1974, the House Judiciary Committee approved three articles of impeachment against Nixon, which were sent to the full House for a vote. In August 1974, Nixon resigned.
Oliver North's testimony
A joint congressional committee was created in January 1987 to investigate the Iran-Contra affair. In July 1987, the committee questioned Lt. Col. Oliver North, a former adviser to national security adviser John Poindexter. North had been dismissed by President Ronald Reagan in November 1986 after his role in the sale of weaponry to the Contras in Nicaragua through intermediaries in Iran was made public.
North testified for almost a a week, with all of the hearings airing live on television. News reports from the time noted that they were highly substantive and highly dramatic.
"I came here to tell you the truth, the good, the bad and the ugly," North said at the outset. "I am here to tell it all -- pleasant and unpleasant, and I am here to accept responsibility for that which I did. I will not accept responsibility for that which I did not do."
Anita Hill's testimony
In 1991, President George H.W. Bush nominated Justice Clarence Thomas to fill the vacancy left by Justice Thurgood Marshall's retirement. During his confirmation hearing before the Senate Judiciary Committee, Thomas' former assistant, Anita Hill, publicly accused the then-nominee of sexual harassment.
"It is only after a great deal of agonizing consideration and sleepless nights that I am able to talk of these unpleasant matters to anyone but my close friends," she said.
In three days of televised testimony, Hill described in explicit detail the harassment she endured during her employment with Thomas in the early 1980s. She also said that he told her to keep quiet.
"He said, that if I ever told anyone of his behavior that it would ruin his career. This was not an apology, nor was it an explanation," Hill recounted. "When I was asked by a representative of this committee to report my experience I felt that I had to tell the truth. I could not keep silent."
Ken Starr's testimony
In January 1998, reports of President Bill Clinton's affair with Monica Lewinsky became public. Clinton denied the allegations at the time, famously saying: "I did not have sexual relations with that woman."
However, in taped grand jury testimony in August of that year, Clinton admitted to "inappropriate encounters" with Lewinsky, but maintained that they "did not constitute sexual relations."
Independent counsel Ken Starr said that Clinton's testimony contained three lies, and thus three instances of perjury
. In November 1998, Starr testified before the House Judiciary Committee during impeachment hearings. His opening statement lasted more than two hours; his testimony lasted 12 hours. In it, Starr alleged that Clinton "repeatedly chose deception."
Hillary Clinton's Benghazi testimony
In late October 2015, Hillary Clinton testified before the House Benghazi Committee
in a marathon hearing. Clinton was questioned on the details of the September 11, 2012, attack that left four Americans dead in Benghazi, Libya. She was also asked about her use of a private email server during the nearly 11-hour showdown.
"I came here because I said I would. And I've done everything I know to do, as have the people with whom I worked, to try to answer your questions. I cannot do any more than that," Clinton said.