More than 600,000 happy people filled the streets of Boston last night, as Jack Kennedy returned home for the last night of his Presidential campaign. The enormous crowd lined both sides of Kennedy's winding two-mile motorcade route from the Statler Hotel to Boston Garden.

When Kennedy entered the Garden, the crowd there maintained 15 minutes of solid, uncontrolled cheering, interspersed with even louder round of "We Want Jack." As the nominee waved to separate sections of the Garden, the audience in each area increased its pitch even higher to an unbelievable crescendo.

After several vain attempts to quiet the 20,000 people jammed into the Garden (no more could have fit), State party chairman John M. Lynch began speaking into the microphone.

Reading his lips was the only way to know that he was introducing Kennedy. When the Presidential candidate then approached the microphone, the crowd roared for five minutes more as Kennedy shook hands with every local official within reach.

The Senator called the roll of Massachusetts' Democratic nominees who drew cheers that seemed mildly wild compared to Kennedy's ovation.

'No Rescue Squad'

"I have brought no rescue squad, I am not running as a protege," continued Kennedy in his latest bread-and-butter speech for committed crowds. He had stressed the same points in New York last wekend.

Kennedy said he admitted his error in accusing the Republican Party of passing no progressive legislation this century "I accept the correction" of a Cleveland newspaper which recalled some items President Taft had supported, "but what have they done since then?" More noise.

The Senator became emphatic and serious, and as he did, the crowd became serious, too. They applauded with an apparent understanding that contrast- ed sharply with their earlier shrieks.

This election "is the most responsible time in the life of every citizen in any country... I have no expectation that the Presidency is an empty or an easy job... The job of the President is to set before the American people the unfinished public business of our country," Kennedy said solemnly.

How can anyone think that sending men on goodwill missions will cause the power struggle among nations to disappear? continued Kennedy. "This whole struggle is far more serious than that ... and I will not go to Eastern Europe but to Washington, D.C., where the job is to be done."

It look more than an hour and a half for Kennedy's motorcade to reach the Garden. Despite the 31-degree weather, the crowd was at least eight deep at almost every point. At Washington and Winter Sts., there was literally no room for any more people to stand. On School St., cars were backed up, unable to move through the crowds.

Without the wooden barricades that New York police use to keep parade routes clear, the Boston police were hard put to contain the crowd at most points. Passing through Dock Square, where a huge spotlight trained on the procession, the motorcade drew to a standstill as the crowds spilled onto the stret.

From Haymarket Square (where Kennedy admirers were setting off scores of loud firecrackers), the streets were again packed solid with sign-brandishing partisans. In front of the Garden, Kennedy stood in his open car to wave up to a crowd at least 200 feet square. The mob overflowed into adjoining side streets and the motorcade had to inch its way up to a side entrance.

Nixon-Lodge headquarters at State and Washington was lit brightly, but very quiet, as the Kennedy motorcade passed. Up the street, a few men displayed flashing, battery-operated campaign buttons.

Visible above the Boston Garden crowd was 6 ft., 5 in. John Kenneth Galbraith, Paul M. Warburg Professor of Economics and a top Kennedy advisor