What was going on when I was born?

AMONG the delegates to the 1980 Democratic National Convention, and among the thousands of people who are coming into town to be somewhere near the action, there must be many for whom a visit to New York is an adventure.

A leaking valve on a tank truck carrying explosive propane gas forced the closing of the George Washington Bridge yesterday and spawned one of the largest traffic jams in New York City's history-- a 30-mile clot of arterial chaos that stretched from Staten Island to the Tappan Zee Bridge in Westchester County.

The Federal judge who was to have presided at bribery-and-conspiracy trials of four members of Congress and other defendants withdrew from the cases yesterday, saying that the "defendants have challenged my ability to decide the motions fairly and impartially."

GARDINERS ISLAND, N.Y.--The 11th-generation descendants of Lion Gardiner and his Dutch wife still have the family Bible, the family silver, the family jewels, the family portraits and the family furniture. But the family island is no longer an undisputed source of happiness, partriarchal or otherwise.

The stock market, fueled by heavy buying by institutions, rose sharply yesterday in one of the heaviest trading sessions in its history.

LOS ANGELES, Aug. 7--Asserting that he was "the first political Secretary of State in a long time," Edmund S. Muskie began a series of speeches around the country today by accusing the Republicans of advocating "a foreign policy of reaction" and of practicing "partisan doubletalk."

Joseph A. Ris abruptly resigned yesterday as chairman and chief executive officer of Korvettes Inc. as a result of the disapproval by the Agache-Willot Group of France, its parent company, of a financial rearrangement of debt Mr. Ris recently worked out with the principal lenders of Korvettes.

SOUTH POINT, Ohio, Aug. 7--This tiny community wedged along a narrow strip of land between the Ohio River and Interstate 52 is a town of few distinctions, marked only by rows of clapboard houses, cinder-block schools and brick churches.

WASHINGTON, Aug. 7 (AP)--Consumer installment debt dropped by a record $3.46 billion in June as Americans apparently remained uncertain about the course of the economy.

THE bootblack stand where George Washington Plunkitt pronounced such tenets of the New York City political creed as the distinction between "honest graft and dishonest graft" stands no more.

Beset by fiscal problems and low productivity, the New York City Department of Sanitation is losing the war against the paper, refuse and rotting fruit that litter the streets of the city.

PROVIDENCE, R.I., Aug. 7--The Outlet Company, barely a puff of smoke on the broadcasting horizon a decade ago, has shifted its attention from its retailing roots toward the more lucrative broadcasting field.