What was going on when I was born?

The United States special envoy to Central America, unable to meet with Salvadoran rebels, today cut short his trip to the area and returned to Washington without explanation. The special envoy, Richard B. Stone, returned to El Salvador this afternoon from Costa Rica, where he had arrived Friday. He had been expected to meet with the rebels. After his return to San Salvador today, he met briefly with President Alvaro Magana and then left for Washington. (In San Jose, Costa Rica, Salvadoran rebel organizations said a meeting between the guerrillas' political leaders and Mr. Stone had been prevented over matters of procedure.)

Winthrop Rockefeller migrated to Arkansas 30 years ago, and soon afterward a correspondent advised him, ''Take your carpetbags and your bank accounts and go back to New York.'' Opinion of the millionaire hillbilly has fluctuated since 1953. Now the historians are ready to enter the judging. The official papers of Mr. Rockefeller, who served as Governor of his adopted state from 1967 to 1971, were opened for scholars with a four-day celebration last week at the University of Arkansas at Little Rock. The current consensus in Arkansas is that Mr. Rockefeller, who died 10 years ago, was considerably more than a playboy carpetbagger. He is seen now as a catalyst and a paver of the way toward political progressivism in this reluctant, ragged, alluring backwater.

A Congressional committee staked out its claim today to take the lead over the White House and the Justice Department in the investigation of how the Reagan Presidential campaign obtained Carter White House documents. The committee moved to secure the original copies of all of such documents found in the Reagan archives at Stanford University. Representative Donald J. Albosta, chairman of the House committee that has been investigating the matter, said the committee acted after former aides to President Carter suggested that the documents might be vulnerable to tampering. Representative Albosta, a Michigan Democrat, said the committee had written to the Hoover Institution on War, Revolution and Peace at Stanford University, where the Reagan papers are stored, asking that originals of any Carter document found in the files be sent to the committee rather than to the White House or the Justice Department.

After an eight-month respite, one of the main culprits in the international debt crisis - interest rates - are on the rise again. Since late May, the six-month London Interbank Offered Rate, or Libor, which determines the size of interest payments on at least two-thirds of the $600 billion debt owed by developing countries to foreign creditors, has risen about a percentage point, to the 10.3 percent level. Morgan Guaranty put the rate as high as 10.5 percent on Friday. With so much debt tied to fluctuations in that short-term rate, the increase that has occurred in the last six weeks would, if sustained over the course of a year, add $4 billion or more to the interest payments of debtor nations, according to financial experts.

The Baldwin-United Corporation, now technically bankrupt as the result of the $617 million first-quarter loss it reported last week, will resist filing for protection from its creditors to avoid the legal wrangling that would be likely to result, the company's president and chief executive, Victor H. Palmieri, said over the weekend. Mr. Palmieri, outlining his immediate plans for the company in an interview Saturday at his Manhattan home, said he wanted to avoid ''all the adversarial fighting that goes on in a court proceeding when you get lawyers in control.'' ''It's a bankrupt company and I'm just saying, 'Why not reorganize it out of court?' '' he said. On Friday, against widespread estimates that it would report a loss of about $100 million for the first quarter, the diversified financial services concern reported that it lost $617 million. Of the total, however, $567 million was attributed to write-offs and $50 million to operating losses.

International Dismissal of Hebron's Arab mayor was endorsed by the Israeli Cabinet. Cabinet officials said the Government would go ahead with a decision to restore the old Jewish quarter in Hebron, a city on the West Bank. The acting Mayor of Hebron, Mustafa Natshe, was dismissed last week by the commander of the Israeli forces in the area after an Israeli student was stabbed to death by a group of Arabs. (Page A1, Column 6.) President Francois Mitterrand is said to have acknowledged mistakes in economic policy since he took office in 1981. According to an article by a French radio reporter, Mr. Mitterrand said the mistakes included a failture to devalue the franc when he first took office and a slowness to undertake an austerity program. He is also said to have found fault with his Socialist Government for underestimating the gravity of the world economic crisis and with himself for expecting too much assistance from President Reagan. (A1:4.)

The Koch administration is considering proposals that would require developers of office buildings and luxury apartments in Manhattan to contribute to a fund for housing in lower-income neighborhoods throughout the city. Under most of the proposals now being studied, developers would pay into the fund in exchange for zoning changes or being allowed extra floor space. Some of the money would stay in the neighborhood where the development is taking place, but most of it would go to other parts of the city. Some proposals being discussed would require all builders in the parts of Manhattan undergoing the most active development to pay into the fund, even if they had not sought zoning changes or bonus floor space.

For the last two years, the Rev. Carl Lundborg, pastor of the First & Summerfield United Methodist Church here, has not paid half of the Federal income tax he owed. Instead, both years, he sent the Internal Revenue Service a letter that read in part: ''My obligations as a Christian and a citizen are no longer reconcilable. The 50 percent of my taxes that support the military I cannot pay.'' A few months after he filed his 1982 tax return this year, an I.R.S. agent visited his home and tried to collect the 1981 taxes due. ''He was very pleasant,'' Mr. Lundborg said. ''But I said I didn't plan to pay the taxes, and I didn't offer any information.''

At the convention of the National Women's Political Caucus today, four Democratic Presidential candidates said that, if elected, they would use political deals and trade-offs to put pressure on states that refuse to ratify the proposed Federal equal rights amendment to the Constitution. While two of the candidates, former Vice President Walter F. Mondale and Senator Ernest F. Hollings of South Carolina, implied that they would use Federal funds to bargain for support of the amendment, the other two, Senator Gary Hart of Colorado and Senator Alan Cranston of California, made that promise explicit, saying they would withhold money for Federal programs and projects from states whose legislatures opposed the amendment. Bidding War for Support A fifth candidate, Senator John Glenn of Ohio, said he would call an ''equal rights amendment summit conference'' at the White House to plan a strategy for passing the amendment, which would ban discrimination based on sex. A deadline for the proposed amendment expired last year without ratification by three-fourths of the states, but it has been reintroduced in Congress.

Greg Louganis stood at the back of the 3-meter diving board at the Air Force Academy Natatorium in Colorado Springs, waiting. As is customary at diving competitions, the spectators were hushed. The divers had finished their five required dives, and now it was time to start the rounds of optional dives -the more difficult ones. Louganis was waiting for the public address announcer to give the usual introduction, identifying the diver, the particular dive he is about to do, and its degree of difficulty, a rating that is then multiplied by the judges' scores to get the score for that dive. At present, 3.5 is the highest degree of difficulty in diving. So when the announcer called out that Louganis's next dive would be a reverse one-and-a-half somersault with three-and-a-half twists, with a degree of difficulty of 3.3, the crowd let out a loud ''Oooooooh.''

The formula for striking it rich used to involve oil wells. Then it was computers. Now the key phrase is health care. Michael Le Coney, a health-care analyst at Merrill Lynch, figures that there is no easier way to raise money than to start a healthcare company. At a clip of something like one a week, new entrants with big dreams and scant revenues are going public. Investors pounce. Stock prices soar. ''Seemingly anybody can do it,'' Mr. Le Coney says. ''It's beyond belief.'' This is the story of how one health-care company - the Genetic Systems Corporation - sprang from a magazine article and a well-timed phone call and has begun to hit paydirt. The Blech Brothers In the summer of 1980, David Blech was a 24-year-old stockbroker on Wall Street. His brother, Isaac, was 30, working in advertising and public relations. Any spare dollars they had, they gambled in hightechnology companies. Their stockpile of money grew. And so one inspired day, David Blech told his brother, let's start a company.

The financial markets are expected to remain edgy this week despite the welcomed $3 billion drop in the money supply that was announced Friday by the Federal Reserve System. While that decline eased pressure on the Fed to tighten credit and possibly drive up interest rates, and while it reduced the possibility of a sharp clash between the central bank and the Reagan Administration, which has been warning the Fed against a tightening of credit, the short-term outlook for monetary policy remains highly uncertain. That is because the money supply has grown to levels far above the Fed's target rate in a period when the economic recovery has been stronger than most economists and officials had expected. As a result, while there is less concern that a tightening of credit will abort the recovery, there is increasing concern that an excessively rapid increase in the money supply will rekindle inflation. The markets thus are focusing their attention on this week's meeting of the Federal Open Market Committee, the arm of the Federal Reserve System that sets monetary policy.