The ongoing impeachment process in the House is naturally bringing to mind other times Congress has weighed removing a president for impeding justice. There were the impeachments of Andrew Johnson and Bill Clinton, of course, but perhaps the most obvious analogue is the one president who resigned before Congress could kick him out: Richard Nixon.

So what did Nixon do exactly that made Watergate so infamous — and how did the scandal itself come about?

Everyone knows that Watergate had something to do with a break-in at the Watergate building in Washington, DC. But it's not really the break-in itself that ended Richard Nixon's presidency so much as the fact that the ensuing investigation revealed a tangled web of wrongdoing of almost unfathomable scale and complexity, implicating the highest levels of the White House up to and including the president.

Veteran journalist Elizabeth Drew covered Watergate in real time, and her excellent book on that period — Washington Journal: Reporting Watergate and Richard Nixon's Downfall — was recently reissued. In 2014, near the 40th anniversary of the resignation, she helped walk us through the trickier points of the scandal and its aftermath. Tim Naftali, the former director of the Nixon Library and current director of the Tamiment Library and Robert F. Wagner Archives at New York University, was also enormously helpful.

1) What was the Watergate break-in?

On June 17, 1972, five men were caught attempting to bug the Democratic National Committee's offices in the Watergate, a residential/office complex in the Foggy Bottom neighborhood of DC.

Three of them were Cuban by background, a fourth was an American who had participated in the botched Bay of Pigs invasion, and the fifth was a former CIA employee. They were found with two listening devices, and two ceiling panels in an office adjacent to that of DNC chair Lawrence O'Brien were removed, suggesting that the burglars were attempting to bug O'Brien's office.

Alfred Cohen, the Washington Post reporter who covered the initial break-in, reported that the suspects were also found with "lock-picks and door jimmies, almost $2,300 in cash, most of it in $100 bills with the serial numbers in sequence … one walkie-talkie, a short wave receiver that could pick up police calls, 40 rolls of unexposed film, two 35 millimeter cameras and three pen-sized tear gas guns." There were two open file drawers in the office when the burglars were caught, presumably because they were attempting to photograph documents.

The break-in — the fourth such attempt, Drew says, with one previous break-in succeeding but not accomplishing the mission at hand — had been planned by Howard Hunt and G. Gordon Liddy at the behest of the Committee to Reelect the President (CRP), Nixon's campaign committee.

Hunt was a veteran CIA operative who had been involved in the agency's successful plot to overthrow left-leaning Guatemalan President Jacobo Arbenz and in the catastrophic Bay of Pigs invasion. Liddy was a former FBI agent turned aspiring Republican politician, who became close with the Nixon election team after a failed 1968 congressional run. Both were members of the team known as the White House plumbers — but more on that in a minute.

Exactly what the burglars were hoping to find, through either photographing documents or bugging the office, is still somewhat unclear. Hunt insisted they were looking for evidence that the DNC was receiving money from the North Vietnamese or Cuban governments. Liddy has recently claimed the plan was to find information embarrassing to White House counsel John Dean.

Perhaps the most popular theory is that Nixon was worried that O'Brien knew about his financial dealings with billionaire tycoon Howard Hughes, for whom O'Brien served as a lobbyist in addition to his DNC duties. A large loan from Hughes to Nixon's brother had become an issue in the 1960 presidential race (which Nixon lost narrowly), and when Nixon took office in 1969, Hughes reportedly gave him $100,000 (about $650,000 today) by way of the president's friend Charles "Bebe" Rebozo, some of which, a 60 Minutes report alleged, went toward Nixon's house in Florida. If that was in fact what the money was used for, it'd be natural for Nixon to fear what O'Brien could do with that knowledge.

There is no smoking gun indicating that Nixon ordered the break-in personally. As Rutgers professor and Nixon expert David Greenberg notes, CRP staff member and Watergate co-conspirator Jeb Magruder claimed to have heard Nixon authorize the break-in, but no hard evidence has turned up to confirm that allegation. However, Nixon certainly created an environment in which criminality was acceptable and even encouraged, and actively participated in covering up the crime.

2) Was the break-in the only crime Nixon's team committed?

Far from it. Nixon's operatives engaged in a whole bevy of criminal activity, much of it targeted at sabotaging his political opponents. His White House had an investigative unit known as the "plumbers" who were tasked with much of this. As White House aide Charles Colson said to Nixon once, "We did a hell of a lot of things and never got caught."

One notorious plumber operation involved breaking into the offices of Lewis Fielding, the psychiatrist of Daniel Ellsberg. Ellsberg, as a government contractor, had contributed to a massive report on the war effort in Vietnam, detailing ways the Kennedy and Johnson White Houses had misled the public about the war, that would come to be known as the Pentagon Papers. He leaked it to the New York Times, the Washington Post, and various senators. Ironically, the break-in led to the dismissal of the espionage charges against Ellsberg, and didn't yield much useful information for the plumbers.

President Nixon mused about using the plumbers to break into the Brookings Institution, a think tank where two other scholars who had worked on the Pentagon Papers (Leslie Gelb and Morton Halperin) worked, so as to retrieve any related documents in their possession; Colson would eventually consider doing the job through a firebombing.

CRP, Nixon's campaign committee, illegally attempted to interfere in the 1972 Democratic primaries in a variety of ways. "They made it their goal to get any stronger candidates eliminated," Drew tells me. "I'm not saying they achieved [George] McGovern's nomination, but that was their goal."

CRP operative Donald Segretti was involved in many of the worst of these efforts, including fabricating multiple documents with stationery from Maine Sen. Edmund Muskie, the 1968 vice presidential nominee and a strong contender for the presidency that year. One accused Sen. Henry "Scoop" Jackson, also a 1972 contestant, of having an illegitimate child with a teenager and of having been arrested for homosexuality. Another slurred French-Canadians as "Canucks," then a potent racial epithet; that damaged Muskie's standing in the New Hampshire primary and contributed to his eventual defeat.

And there was more that simply never got unearthed. There's tape of Colson bragging about blackmail efforts where even Nixon sounds surprised — but on the tape, Colson swears he'll take those secrets to his grave, and he seems to have kept his word (Colson died in 2012). Reviewing John Dean's book The Nixon Defense, Bob Woodward wrote that "the full story of the Nixon administration's secret operations may forever remain buried along with their now-deceased perpetrators."

3) Who found out the White House was involved in the break-in?

The White House's involvement was unearthed through a combination of government investigations into the break-in and investigative reporting by the Washington Post's Carl Bernstein and Bob Woodward. Within days of the break-in, Bernstein and Woodward figured out that one of the five men arrested for the crime, James McCord, had a contract to do security for the Republican National Committee, and had connected the burglars to Hunt, and Hunt to Colson.

On August 1, they reported that a $25,000 check earmarked for the Nixon campaign made its way to the bank account of Bernard Barker, who was also arrested in the break-in. By September, they had uncovered a secret slush fund used by former CRP head and Attorney General John Mitchell to investigate Democrats, and by October they knew about Segretti's sabotage efforts.

On September 15, 1972, the five burglars, Liddy, and Hunt were indicted by a federal grand jury. By January 1973 — after Nixon was reelected in a landslide, winning every state but Massachusetts and the District of Columbia — Hunt and the four of the actual burglars had pleaded guilty, and Liddy and McCord were found guilty after a trial.

But John Sirica, the district court judge who tried these defendants, stated he was "not satisfied" the full story of the break-in had been told, and on February 7, the Senate voted unanimously to create a temporary ("select" in Congress jargon) committee, chaired by Democrat Sam Ervin of North Carolina, to investigate the break-in.

It became clear that the conspiracy — and, in particular, the cover-up — reached higher in March 1973, when McCord sent a letter to Sirica alleging a high-level cover-up and suggesting he feared retaliation if he were to "disclose knowledge of the facts in this matter." That same month, L. Patrick Gray, the acting FBI director, testified during his confirmation hearings to become permanent director that he had provided White House counsel John Dean with files concerning the FBI's investigation into the break-in, and that Dean had "probably lied" to investigators. From that point, it wasn't long before senior aides to the president began to be forced out for their involvement.

Gray himself resigned after it came out that he, at the behest of Dean and White House domestic policy adviser John Ehrlichman, had destroyed files from a safe belonging to Hunt. On April 30, Nixon fired Dean and accepted the resignations of his chief of staff, H.R. Haldeman, and Ehrlichman, as well as his attorney general, Richard Kleindienst, while insisting that this did not constitute an admission of wrongdoing on the latter three staffers' parts.

By that point, however, Dean was actively cooperating with investigators, and would tell them that Nixon had actively participated in covering up the crime — an allegation later proven with tapes of White House conversations (but more on that later).

4) How did the White House try to obstruct investigations?

It's impossible to list all the varied ways the White House attempted to impair investigations from the grand jury, from the special Senate committee eventually formed to deal with the scandal, and from the independent counsel appointed to investigate the affair. But here are a few:

Within days of the break-in, Nixon decided to ask the CIA to disrupt the FBI's investigation of the incident, on the grounds that it concerned matters of national security; the CIA, however, resisted the order.

Throughout the FBI's early investigation, White House counsel Dean sat in on interviews with witnesses and got regular updates from Gray.

The White House paid hush money to co-conspirators, including $75,000 to Hunt personally; Nixon was caught on tape discussing the arrangements with Dean.

Nixon tried, to no avail, to have aides manufacture dictatape evidence to give to Judge Sirica.

Nixon implied to Ehrlichman that they should prevent Dean from continuing to cooperate with investigators by offering him clemency in exchange for keeping his mouth shut.

Ehrlichman ordered Colson to offer clemency to Hunt in exchange for silence.

Later, when it came out that there was hard tape evidence concerning Nixon and other aides' roles in the cover-up, the administration took extraordinary measures — including going to the Supreme Court and attempting an unprecedented quashing of a Justice Department investigation — to prevent it from coming to light. But more on that in a sec.

5) Can we take a quick music break?

Of course. The period from 1972 to 1974 was generally excellent for American music, but you wouldn't really know it from the singles charts. Case in point: The No. 1 record at the time of the break-in was Sammy Davis Jr.'s "The Candy Man," which, while inspiring an excellent Simpsons number years later, is mostly an enervating bit of treacle without much going for it:

Nonetheless, "The Candy Man" is still preferable to the chart topper when Nixon resigned, John Denver's "Annie's Song":

It sold basically no copies upon initial release, but June 1972, the month of the break-in, saw the release of Big Star's #1 Record, my favorite record of all time and a power-pop classic. You can listen to the whole thing on Spotify. Here's the opener, "Feel":

6) What were the White House tapes?

While the Kennedy and Johnson White Houses had done some taping of presidential meetings, the Nixon administration was the first and only one to record the president's activity so completely (though his bedroom and residences in San Clemente and Key Biscayne were not taped). As former White House aide Alexander Butterfield — by then Federal Aviation Administration chief — testified before the Senate Watergate Committee in July 1973, the system began recording in the spring of 1971, and was activated by sound. Few people in the White House other than Nixon knew they were being recorded:

The tapes represented the single best source of evidence into the White House's involvement in the break-in, and as such, the administration tried desperately to prevent the Senate Watergate Committee or the independent counsel whom the attorney general had by then appointed to investigate the incident from getting ahold of them.

It ultimately took a unanimous Supreme Court ruling following the independent counsel's securing of a subpoena against the president to force their release. They contained what became known as the "smoking gun" recording, in which Haldeman and Nixon, days after the break-in, discuss using the CIA to hamper the FBI's investigative efforts. Within days of the public learning of the smoking gun tape, Nixon resigned from the presidency.

The tapes included an 18½-minute gap on June 20, 1972. The minutes are believed to include a conversation between Nixon and Haldeman about the Watergate arrests. Rose Mary Woods, Nixon's secretary, claimed that she accidentally erased the portion, but when she was asked to demonstrate how exactly that would have happened, the circumstance was so physically implausible that most discounted that explanation. Most plausible, according to Drew, is Ehrlichman's allegation that Nixon personally erased the tapes, presumably because they contained discussion of a cover-up.

In recent decades, as more and more tapes were made available to the public, journalists, and scholars by the National Archives, non-Watergate revelations about the Nixon presidency emerged. Nixon's anti-Semitism is on full display in the tapes, for example, and they also confirm Nixon and Henry Kissinger's support for the genocide being conducted by Pakistan's military government against Bangladesh in the latter's war for independence. Most recently, a tape of Nixon discussing panda sex garnered some attention.

7) What was the Saturday Night Massacre?

The fight for the tapes was mainly conducted between the Nixon administration and the independent counsel in the Justice Department appointed to investigate the Watergate break-in. The first such counsel was Archibald Cox, a former solicitor general from the Kennedy administration and a Harvard law professor. Cox subpoenaed the tapes, and the White House refused to comply, offering instead the "Stennis Compromise": John Stennis, a conservative Democratic senator from Mississippi, could listen to the tapes and verify they matched transcripts released by the White House. But Stennis was notoriously hard of hearing, and Cox would not agree to the deal.

What happened next was arguably one of the most brazen abuses of presidential power in American history. Nixon ordered his attorney general, Eliot Richardson, to fire Cox. Richardson refused, resigning instead. The new acting attorney general, William Ruckelshaus, refused as well, and resigned. The third in command at the Justice Department, Solicitor General Robert Bork (whom Ronald Reagan would later try and fail to appoint to the Supreme Court), finally carried out the order to fire Cox. The office of special prosecutor was abolished, and the investigation was sent back to the Justice Department proper.

The reaction to the events was furious. "It was a terrifying night," Drew says. "It felt like we were in a banana republic."

"The television networks offered hour-long specials," Woodward and Bernstein write in their book The Final Days. They continue:

The newspapers carried banner headlines. Within two days, 150,000 telegrams had arrived in the capital, the largest concentrated volume in the history of Western Union. Deans of the most prestigious law schools in the country demanded that Congress commence an impeachment inquiry. By the following Tuesday, forty-four separate Watergate-related bills had been introduced in the House. Twenty-two called for an impeachment investigation.

The reaction forced Nixon to appoint a new special prosecutor, Leon Jaworski, who would eventually succeed in his quest for the tapes.

8) What crimes did the House attempt to charge Nixon with?

The House Judiciary Committee approved three articles of impeachment against Nixon. It's worth remembering that Nixon was never actually impeached or convicted. Impeachment (the equivalent of an indictment in a normal trial) would have required a majority vote of the House, and removal from office a supermajority vote of the Senate. Nixon resigned before either could occur. That said, there was no question the votes were there to impeach him, and quite likely to remove him from office as well.

The first article approved by the House committee charged him with "engag[ing] personally and through his close subordinates and agents, in a course of conduct or plan designed to delay, impede, and obstruct the investigation of [the Watergate break in]; to cover up, conceal and protect those responsible; and to conceal the existence and scope of other unlawful covert activities."

The second article charged him with a variety of abuses, including attempting to use the IRS to investigate political enemies, using the FBI to do illegal surveillance, overseeing the break-in to Ellsberg's psychiatrist's office, and allowing the plumbers to work in the White House in general. The third article concerned his failure to comply with subpoenas from Cox, Jaworski, and the Senate Watergate Committee.

The first article was approved on July 27, 1974, very shortly before Nixon resigned, which rendered the impeachment process moot.

9) Who was punished for the break-in and similar wrongdoing?

More than a dozen White House officials and co-conspirators were charged with crimes relating to the Watergate scandal:

Chief of Staff H.R. Haldeman, Nixon's closest aide, served 18 months for conspiracy and obstruction of justice.

Former attorney general and reelection campaign manager John Mitchell was found guilty of conspiracy, perjury, and obstruction of justice. He served 19 months in prison.

White House counsel John Dean only served four months for conspiracy to obstruct justice, due to his cooperation with investigators.

Domestic policy adviser John Ehrlichman was convicted of conspiracy to obstruct justice and perjury with regards to Watergate, and conspiracy in the case of Ellsberg's psychiatrist. He served 18 months.

Howard Hunt served 33 months for burglary, conspiracy, and wiretapping, to which he pleaded guilty.

G. Gordon Liddy, who refused to plead guilty, was sentenced to 20 years for Watergate, Ellsberg, and contempt of court, but that was commuted by Jimmy Carter, and he wound up serving only four and a half years.

Donald Segretti, Nixon's campaign operative/saboteur, served four and a half months after pleading guilty to three counts of distributing illegal campaign literature.

Chuck Colson, who was involved in putting together the plumbers and covering up the break-in, got seven months after pleading guilty to obstruction of justice. He went on to become a born-again Christian and vocal prison reform advocate.

Fred LaRue, a Nixon campaign adviser involved in the provision of hush money to participants in the break-in, pleaded guilty to obstruction of justice and served four and a half months, a reduced sentence due to his cooperation.

Jeb Magruder, a White House aide turned campaign aide who helped plan the break-in with Liddy, served seven months, and went on to become a Presbyterian minister.

Nixon was never prosecuted for his role in the scandal due to a blanket pardon granted by his former vice president, Gerald Ford, shortly after Ford assumed the presidency.

Update: After this explainer’s initial publication in 2014, Tim Naftali, former director of the Nixon Library, identified a few points of clarification, which have been incorporated into the post, including the fact that McCord turned on his co-conspirators in March 1973, that Nixon rather than Nixon and Haldeman decided to ask the CIA to disrupt the investigation, and that the CIA refused to cooperate before the FBI figured out the plot. We regret the errors concerning Nixon's request for CIA interference, and thank Mr. Naftali for his extensive help and additional details.

In addition, journalist Elizabeth Drew wrote in with additions after publication, including noting that the votes were likely there for impeachment and removal, and that Ehrlichman believed the gap in the tapes was caused by Nixon himself erasing them. We thank her for her extensive assistance.