The House Judiciary Committee took the momentous step last night of recommending that the president of the United States be impeached and removed from office.

The first such impeachment recommendation in more than a century, it charges President Nixon with unlawful activities that formed a “course of conduct or plan” to obstruct the investigation of the Watergate break-in and to cover up other unlawful activities.

The vote was 27 to 11, with 6 of the committee’s 17 Republicans joining all 21 Democrats in voting to send the article to the House.

At least one other article accusing the President of abuse of power is expected to be approved Monday when the committee resumes.

But approval of a single article is all that is required to send the issue to the House. And approval of a single article by a majority of the House is enough to impeach the President and send the case to trial in the Senate, which could remove Mr. Nixon from office by a two-thirds vote.

The bipartisan support for the article adopted last night makes impeachment by the House seem more than likely. The majority included three conservative Southern Democrats and three conservative Republicans.

In San Clemente, Calif., White House press secretary Ronald L. Ziegler said after the vote that Mr. Nixon remains confident that the House will recognize he has not committed an impeachable offense.

But Senate Democratic Leader Mike Mansfield said he will meet Monday with Minority Leader Hugh Scott to launch formal Senate preparations for an impeachment trial.

“The line of demarcation has been reached,” he said.

Most members of the Judiciary Committee cast their votes in low, solemn tones and afterward spoke almost in awe of what they had done.

“It’s a grave and sobering decision,” said Rep. Paul Sarbanes (D-Md.), who had managed the debate on Article I for the impeachment forces as an author of a substitute article.

“I don’t feel very good about it,” said Rep. Tom Railsback (R-Ill.), one of the key Republicans who voted against the President.

Some Republican opponents of impeachment were angry. “It’s not only a bad day for the presidency, it’s a bad day for American justice,” said Rep. Delbert Latta (R-Ohio). He complained that the article of impeachment did not contain enough specific allegations.

“We have weakened the hand of the President and the 220 million people he represents,” said Rep. Joseph Maraziti (R-N.J.), one of Mr. Nixon’s most persistent supporters.

Other anti-impeachment Republicans vowed to fight the impeachment article when it comes to the House floor. “It’s only Round One,” said Rep. David W. Dennis (R-Ind.). “There’ll be a good scramble in the House.”

Even those whose impeachment votes were never in doubt voiced no sense of triumph. “I don’t want to talk to anybody,” Rep. Barbara Jordan (D-Tex.) said. “It’s a terrible thing to happen to anybody,” said Rep. Charles B. Rangel (D-N.Y.). “I’m not happy,” said Chairman Peter W. Rodino (D-N.J.).

Just before the historic vote, Rep. Walter Flowers (D-Ala.) revealed for the first time he had decided to vote for impeachment. He said that after weeks of searching the facts and the Constitution “it is clear to me what I must do.” He said some of his constituents would feel hurt by his vote against the president but he assured them that, “I probably have enough pain for both them and me.”

Rep. Hamilton Fish (R-N.Y.) also disclosed he would vote for impeachment. He said he reached that point “with deep reluctance,” but added. “The evidence is clear.”

It took two votes -- one to substitute the amended Sarbanes version for the original resolution and then one to approve the impeachment article. The vote ended at 7:05 p.m.

The article specified nine categories of unlawful activities that were allegedly part of the cover-up.

“In all this,” the article concluded, “Richard M. Nixon has acted in a manner contrary to his trust as President and subversive of constitutional government, to the great prejudice of the cause of law and justice and to the manifest injury of the people of the United States.

“Wherefore Richard M. Nixon, by such conduct, warrants impeachment and trial and removal from office.”

During the four days of general debate and amending of the article, the principal witness was the absent President himself. Time after time, committee members picked up transcripts of taped presidential conversations to read back the President’s words.

And even more often they would note a gap in the evidence caused by the President’s refusal to comply with committee subpoenas that he turn over more tapes.

The articles of impeachment will go to the House headed by a resolution, which in its present draft form reads:

“Resolved, that Richard M. Nixon, president of the United States, is impeached for high crimes and misdemeanors, and that the following articles be exhibited to the Senate: . . .”

The impeachment inquiry, which began seven months ago, was provoked principally by Watergate but other issues covered by a proposed Article II charging abuse of power cause more concern among some members.

Some Republicans are most concerned about allegations that Mr. Nixon misused such sensitive agencies as the Internal Revenue Service and the Central Intelligence Agency for political purposes.

Others are most concerned about Mr. Nixon’s defiance of committee subpoenas, which is now included in Article II as a contempt of Congress count, but may be broken out into a separate article. An attempt may be made to offer a fourth article on tax evasion, but it is not expected to be approved.

The obstruction of justice article approved last night accuses Mr. Nixon of making false statements to investigators, withholding relevant evidence, approving or counseling perjury, interfering with the Justice Department’s investigation, approving payment of hush money to Watergate defendants, passing on information about the investigation to his aides who were suspects, making false statements to the American people about White House involvement in Watergate and causing defendants to believe they might receive clemency for the silence.

The Democratic majority and a few Republicans spent the afternoon on national television reciting instance after instance in which they said Mr. Nixon and his former top aides withheld information on the cover-up and tried to interfere with various investigations.

The committee yesterday rejected a half dozen amendments that would have deleted most of the nine paragraphs in Article I alleging obstruction of justice.

It was a pro forma debate, insisted upon by Rep. Flowers who said the committee had an obligation to build a record describing the specific offenses committed by Mr. Nixon and his aides.

One major amendment was passed. It charged that Mr. Nixon had personally and through aides engaged in a “course of conduct” designed to obstruct investigation of the cover-up. That language replaced a charge, considered more difficult to prove, that Mr. Nixon had formulated a specific “policy” to obstruct justice.

Another amendment added “congressional committees” to the list of organizations whose investigations Mr. Nixon was alleged to have interfered with.

The sharp debate on evidence yesterday was in contrast to the rambling arguments that characterized Friday’s committee deliberations.

The Republican minority Friday demanded more specific facts in the charges lodged against Mr. Nixon in Article I. Unprepared, the Democrats and a few Republicans tried to contend the impeachment article didn’t need specific citations of evidence to back it up.

But yesterday the Democrats were prepared in depth to give specific reasons Mr. Nixon should be impeached for obstructing justice in the Watergate cover-up. Different members had been assigned the task of defending each numbered paragraph in the charge and obviously were delighted to pour out the evidence before a national television audience.

Rep. Charles Sandman (R-N.J.), the Republican who had sought Friday to strike each paragraph one by one, backed down quickly yesterday, acknowledged he lacked the votes to win, and said the committee should go ahead and vote on the whole article.

But Flowers insisted that the committee had to build a record of evidence and demanded a debate and vote on each of Sandman’s amendments.

The first amendment Flowers offered yesterday was to eliminate a paragraph charging that the cover-up plan included “withholding relevant and material evidence of information (on the break-in) from lawfully authorized investigative officers and employees of the United States.”

Rep. William Cohen (R-Maine) promptly began rattling off evidence to show that Mr. Nixon and his top aides had withheld such information.

Cohen said that shortly after the June 17, 1972, break-in Mr. Nixon and his aide, John D. Ehrlichman, knew that men from the Committee for the Re-election of the President were involved. “These facts were withheld from the Attorney General and other investigators,” he said.

There was also physical evidence in the White House -- a memo from H.R. Haldeman, chief of staff, a phone book containing E. Howard Hunt’s name, and a copy of a political intelligence plan -- that was destroyed or altered, Cohen said.

He also recalled that former Attorney General John N. Mitchell told Mr. Nixon he was sorry he hadn’t supervised more closely re-election committee employees who were involved and that Mr. Nixon had noted that information in one of his Dictabelt recollections.

Cohen also said that on March 13, 1973, Mr. Nixon was told that a White House aide, Gordon Strachman, had committed perjury, but he failed to report that information to investigators.

Reps. Dennis and Wiggins led the counter-attach, arguing that Cohen’s list of evidence implicates Mr. Nixon’s aides but not the President himself in withholding information.

Ehrlichman, Mitchell and Haldeman all had something to cover up, but the President didn’t, Dennis said. He said the President didn’t know anything about details of the cover-up until told of it on March 21, 1973, by his counsel, John W. Dean III.

Wiggins contended that even the famous March 21 conversation with Dean didn’t implicate the President. He argued that, in context, the conversation showed Mr. Nixon anxious to have the policy of withholding,” Wiggins said.

But Mr. Nixon had learned on March 13 of Strachan’s perjury, countered Rep. John Seiberling (D-Ohio). “Did the President rise up in righteous indignation?” asked Seiberling. “He did nothing.”

The move to strike the paragraph on withholding evidence was defeated on an overwhelming voice vote.

The only major substantive change in Article I voted yesterday was designed to make it more palatable in the Senate if Mr. Nixon should be brought to trial there.

Originally the article charged that Mr. Nixon “made it his policy” to obstruct the investigation of Watergate and to protect those responsible.

An amendment introduced by Railsback charged instead that the President engaged “in a course of conduct or plan designed” to impede and obstruct the investigation.

Railsback said he had difficulty believing that Mr. Nixon at any specific time formulated a policy of obstruction, but he said the record shows a “course of conduct” amounting to obstruction.

Dennis observed that Railsback’s amendment cited a “plan” of obstruction and asked: “What’s the difference between a policy and a plan?”

Railsback acknowledged he also had trouble judging the difference, but said that committee counsel believed that the word “policy” had the connotation of an “orchestrated” effort to obstruct.

“I believe that certain events occurred to which Mr. Nixon didn’t respond or responded to in an improper way,” Railsback added.

Did Railsback mean Mr. Nixon intentionally acted in such a way as to delay or impede the investigation? Wiggins wanted to know. Railsback said he meant that Mr. Nixon acted knowingly for the purpose of delaying and impeding it.

Rep. Wayne Owens (D-Utah) said he was satisfied that obstruction was a deliberate policy of the President but said that the new language would “make proof in the Senate easier.”

Railsback’s amendment was approved on a voice vote.

The only other substantive amendment was one by Rep. George E. Danielson (D-Calif.). It accused Mr. Nixon of interfering or trying to interfere with investigations by congressional committees. The original article had said he interfered with investigations by the Justice Department; the FBI, and the Watergate Special Prosecution Force.

Danielson charged that Mr. Nixon tried to interfere with the investigations planned or launched by the House Banking and Currency Committee, the Senate Watergate Committee, and the House Judiciary Committee.

Wiggins countered that there never was a Banking and Currency Committee investigation for Mr. Nixon to interfere with. The only evidence he tried to interfere with the Senate Watergate committee, Wiggins said, consisted of his considering withholding witnesses through claims of executive privilege, claims that were finally relinquished.

Danielson claimed Mr. Nixon interfered with the Judiciary Committee by withholding tapes and documents. Wiggins said the President was merely making a “good faith claim” to executive privilege by withholding these pieces of evidence.

Danielson’s amendment was adopted 24 to 14, with supporters and opponents of impeachment winding up on both sides of the issue.

Two minor amendments offered by Rep. Lawrence Hogan (R-Md.) were approved on voice votes. One changed “illegal” entry to “unlawful” entry. Another related to a charge that the obstruction involved the making of false statements to investigators; Hogan’s language added the phrase “or causing to be made.”

After a mid-afternoon recess, Flowers agreed to limit debate to 20 minutes on each of his amendments to strike sections. And he passed over some without amendment. His amendments were beaten back by votes of better than 2 to 1. Flowers himself voted “Present,” rather than no, to show he wasn’t really trying to knock out the numbered charges, but rather to produce specific incidents of improper conduct.

Opposing an amendment to strike a section stating that the President condoned or counseled perjury. Rep. M. Caldwell Butler (R-Va.) read rapidly from the transcript of Dean’s March 21, 1973, meeting with the President.

Butler noted that Dean told the President that Jeb Stuart Magruder and Herbert Porter, at the re-election committee, had committed perjury before the Watergate grand jury and that the President expressed no opposition to it. He also read from a March 27 transcript where the President’s top aide, Haldeman, asked Mr. Nixon whether Dean “should stay with the old lie” and the President replied, “What would you advise him to do?”

Wiggins defending the President, said Mr. Nixon had learned of Magruder’s and Porter’s perjury after the fact and so had not “counseled” it. The section also contained the words “approving, condoning, acquiescing in . . .” Wiggins said “two reasonable possibilities” must be resolved in favor of the president.

Flower’s pro forma effort to strike a section charging the President with attempting to interfere with the Justice Department and FBI Watergate investigation was strongly opposed by Hogan, a former FBI agent.

Hogan recited events starting June 23, 1973, when the President directed Haldeman and Ehrlichman to meet with top CIA officials and instruct them to relay to the FBI White House concern that the FBI Watergate investigation in Mexico might expose CIA activities there. The CIA reported back that there was no jeopardy to the CIA.

But the President’s counsel, Dean, persisted in trying to keep the FBI out of Mexico, Hogan said. The reason, he said, was that the investigation would have traced money found on the Watergate burglars through a laundering process in Mexico and back to the re-election committee. After this, acting FBI Director Patrick Gray told Mr. Nixon his aides were trying to “mortally wound” him, but the President didn’t even ask what he meant, Hogan said.

Wiggins responded that the President naturally had concern about possible CIA involvement in the Watergate break-in because of the CIA background of several of the burglars.

Wiggins said the President’s concern was that covert CIA operations not be exposed, not that the trail of the money be covered.

And when Mr. Nixon talked with Gray, said Wiggins, he properly responded that Gray should “continue your investigation.”

The President’s critics try unreasonably to make something of a “perceptible pause” before Mr. Nixon replied to Gray’s “mortally wound” remark, said Wiggins.

House Majority Leader Thomas p. O’Neill (D-Mass.) has repeatedly predicted that if the committee recommended impeachment, the House would vote to impeach the President by a margin of 50 votes or more.

Democrats on the Judiciary Committee are more liberal than House Democrats as a whole, and committee Republicans are more conservative than the House Republicans generally.

But Southern Democrats on the committee -- James R. Mann of South Carolina, Flowers of Alabama and Thornton of Arkansas -- are highly respected by their colleagues and should help make a vote for impeachment respectable among their Southern colleagues except for a relatively small group of about 25 conservatives who appear to have adopted an attitude of “never.”

Similarly, committee Republicans like conservative Hogan, respected Southerner Butler, and Midwestern moderate Railsback, should be persuasive with various groups of Republicans in the House.

After the Judiciary Committee completes its work, it must write a report explaining to the House in detail why it has recommended impeachment. The committee will then go to the House Rules Committee a week later to get a resolution fixing ground rules for debate on the floor.

The House is expected to debate the articles about two weeks under the rule, permitting amendments as the committee procedure did, and vote about Aug. 24.

If the case goes to the Senate, the trial is expected to last about two months, preceded by a delay to permit the President’s lawyers to prepare his defense.