On the seventh day, as autumn winds lapped across the Mall of Washington and the late afternoon sun withdrew behind somber clouds, Pope John Paul II, in his farewell mass for America, was both warm in heart and stern in message.

"Peace be with you," said John Paul II.

And from the 175,000 in his audience -- the Catholics, the curious and the awed, wearing winter suits and Sunday dresses, Knights of Columbus slickers and hometown letter-jackets, cloth scarves and Texas cowboy hats -- came the traditional reply:

And also with you."

But within the next 30 minutes, as this charismatic pope delivered the final homily of his American journey, he firmly pounded out a theme that has brought anything but peace in this country. In unemotional voice, again and again, he spoke out against birth control and abortion.

"I do not hesitate to proclaim before you and before the world," he said, "that all human life -- from the moment of conception and through all subsequent stages -- is sacred, because human life is created in the image and likeness of God."

With that one sentence, hundreds who had come to see him packed up their belongings and left for home. Some said they were tired and cold. But others said they were distraught that, for his final message, the pope would choose a subject so political and controversial.

"Thousands and thousands of children are starving around the world," said one woman from Alexandria as she made an early and sad departure from the Mall."And there he is advocating having more and more children."

This was a minority view, on the Mall at least, and most in the smaller than expected audience stayed and cheered as they looked up to their spiritual leader, his white hair touched by the breeze, his stolid face and green vestments framed against the bright whiteness of the immense platform.

Five more times during his homily, the pope would present his antiabortion case in unmistakable terms, until finally, in one long summary statement, he elicited a sustained and thunderous applause from those among him who were there not as spectators but as participants in the most important rite of worship for Roman Catholics.

"And so," said the pope, his voice echoing across the mall from hundreds of loudspeakers, "we will stand up every time that human life is threatened. When the sacredness of life before birth is attacked, we will stand up and proclaim that no one ever has the authority to destroy unborn life."

From the solemn celebration on the mall, the pope returned by limousine to the Apostolic Delegation on Massachusetts Avenue, where he relaxed and reflected for a short time before taking a helicopter to Andrews Air Force Base. There, in the cold October night, seven days after his extraordinary journey through America began, Pope John Paul II bade a quiet goodbye and flew off for Rome.

The subdued and serious nature of the mass and all that followed were in marked contrast to the festive atmosphere on the Mall in the 24 hours before the pope and about 200 white-robed bishops arrived for the mass.

As early as Saturday afternoon, hundreds of people claimed squatters' rights on the grounds surrounding the chain link fence that protected the platform. Parents and their children, young couples and bands of young men and women unfolded their sleeping bags and began a joyous vigil until the next afternoon.

They brought the amusements of their daily lives with them -- playing cards, backgammon sets, footballs, sandwiches and drinks, guitars, even battery-operated television sets. By midnight, the faithful campers had formed a 20-yard-wide encirclement of the platform. Most in the crowd were young, and as the guitars played and the voices rose in song, there was a sense that this was a bit of Woodstock -- but without any scent of marijuana.

When, at two minutes after midnight, a young man got up and shouted, "This boy over here turned 14 two minutes ago," everyone present, in delightful harmony, offered him a verse of "Happy Birthday to You."

"What a wonderful feeling," said Elizabeth Bechthold, the boy's mother. "We came down here from our home in Adelphi this morning and have had a terrific time. I've never seen anything like this in Washington before."

"Oh, come on, mom," said her oldest daughter. "What about Martin Luther King's speech."

Indeed, in the days before this mass amid the monuments of the nation's capital, city officials, Catholic leaders and local newspapers predicted that this event would attract up to one million people -- far exceeding the civil rights and peace demonstrations that brought hundreds of thousands to the Mall in the 1960s and early 1970s.

But by early this morning, it was clear that the predictions would prove much too high.At 10 a.m., there were no more than 15,000 people on the Mall, and by noon -- when city officials feared that downtown would be one massive traffic jam and the subways would be overcrowded -- the streets were barren only two blocks from the Mall and Metro's cars were less crowded than on the average workday.

It was between noon and 3 p.m. that the flow of people toward the Mall surged. They were pilgrims from nearly all points east of the Mississippi, traveling here in chartered buses from the row houses of Union City, N.J., and Baltimore, in vans nicknamed Shepherd II, in honor of the pope's plane, from Tupelo, Miss., in overloaded station wagons from Appalachia, Va.

Albert DeMichele, a deputy sheriff from a small town in New Jersey, stood poised behind a 500-millimeter lens mounted on a six-foot tripod. He looked across the Mall toward the stage from his perch near the National Archives and muttered, "Beautiful. The sun shone brightly through blue-gray skise and hundreds of people strolled slowly along the Mall's tan dirt paths, past vendors hawking almost every souvenir known to man, past the majestic museums that grace the area. Within 100 yards of the stage, in front of the ivy-covered Smithsonian Castle, the crowds were dense. But elsewhere on the Mall, people moved about freely.

By four o'clock, when the pope finally arrived, an hour behind schedule, the sun had lost its fight with the clouds, the winds blew colder, and the crowd that was once expected to reach a million had grown to no more than 175,000. Still, in normal terms this is not a small figure, and there were many in the crowd who could not see John Paul's entrance.

"We were close, about 200 feet from the altar," said Andrew Obferbank of West Caldwell, N.J. "But we still couldn't see. Oh, from time to time, someone would move and we'd get a glimpse."

A glimpse of the pope was the most that many had hoped for, and once they saw him, they headed home, not waiting through the ritual of the mass, from the "Peace be with you" greeting to the penitential rite of confession, the prayer, the liturgy, the homily, the profession of faith, the general intercession, the liturgy of the Eucharist, more prayers and then communion.

The communion service on the Mall was most unusual. Some priests handed the unleavened bread, known as the Host, which Catholics believe to be the body and blood of Christ, to one person, who would then have it passed through the crowd to a communicant. Normally, the Host is swallowed immediately, without being touched by anyone other than the priest delivering the Host and the communicant.

Those who did stay, listen and participate were for the most part joyous as they left for home. "He was just fabulous," said Barbara Jeffers of Laurel. "He reminded me of when Jesus Christ was on earth, preaching to the people."

Margaret Schilpp, a 62-year-old woman from Baltimore, left the Mall with a pope button on her coat, a pope pennant in her hand and a pope bumper sticker in her purse. "He's a brilliant man," she said, before boarding one of 93 buses chartered by the Catholic churches of Baltimore. "He's a leader of peace and a man of charm."

"This was the closest you can come to God outside of going to heaven," said Kay Sim of Chevy Chase, who had come to the mass with her husband, son, daughter-in-law, five children and assorted friends. "You felt you were in the presence of God here."