Paula Davis sat in a portable chair at the gravesite of her only child on Monday and called out a greeting to a woman passing by.

“She’s my neighbor,” she said, referring to a nearby headstone in Section 60 of Arlington National Cemetery. “Neighbor and friend.”

This is the 15th year that Davis, 67, of Gaithersburg, Md., has been coming here, and during that time, she has become close with others like her, people who have lost a child, a sibling, a spouse or a parent in the military.

They know about her son, Pfc. Justin Ray Davis, who died in Afghanistan in 2006 at age 19. How he used to call his mom “the paparazzi” because she took so many pictures of him. How he had planned to move to Los Angeles after his service and become an actor. How he had always wanted to serve his country.

Last year on Memorial Day, there was hardly anyone to tell it to. The cemetery, where 400,000 members of the military and their family members are buried, was closed to the general public. Many family members stayed away as the pandemic curtailed travel and other public activities. It has reopened in steps, with the general public being allowed on the grounds starting in September and tour buses starting in April. Last week, the Tomb of the Unknowns, President John F. Kennedy’s gravesite and exhibits in the welcome center fully opened to the public.

A cemetery spokesperson said about 10,000 people were expected to have visited by the end of the day. That is fewer than the 18,000 to 20,000 who typically come on Memorial Day. But a year ago, just 4,149 people, mostly family members, came for the holiday.

“There was hardly anybody here and it was strange, weird, because it’s always crowded,” Davis said. The smattering of families “had on masks and we were fist-bumping” instead of giving the usual hugs.

But on Monday, families gathered mask-free beside graves, spread out blankets, and placed mementos and flowers beside them. A group of women sang Tibetan chants beside a grave. Families chatted as small children played around them. Some people just stood and bowed their heads.

“This year, it’s like, ‘Oh, wow, we’re back,’ ” Davis said, beaming. “Now it’s lots of hugs. It definitely is a different feeling.”

Earlier that morning, President Biden had been at the cemetery and delivered a rousing defense of democracy and a plea for unity, saying “democracy is more than a form of government — it is a way of being.”

“Democracy itself is in peril,” the president said.

Speaking for roughly 20 minutes, Biden said the American soldiers buried around him, and around the world, gave their lives to uphold the U.S. Constitution and the country’s form of government.

“Democracy must be defended at all costs,” Biden said. “Democracy, that’s the soul of America. And I believe it’s a soul worth fighting for. And so do you. A soul worth dying for.”

Biden also referred to the threats to the country’s form of government.

“The soul of America is animated by the perennial battle between our worst instincts, which we’ve seen of late, and our better angels.”

He urged patriotism, saying there is a struggle “between ‘me first’ and ‘we the people.’ ”

As his motorcade left the cemetery, Leslie Aalto, 39, of Minneapolis, and her husband and two young sons stood on the roadway, craning their necks as the president and first lady Jill Biden waved.

“We just got lucky!” Aalto said after they passed. “It felt exhilarating. He’s such a military guy, and it’s such an honor to know that he is here paying tribute.”

They had come to introduce their younger son, Julian, 1, to the great-grandfather he is named after, a World War II hero who landed at Normandy Beach. A great-uncle is also buried there.

“After a year like this, it’s a good reminder that when things get tough, you roll up your sleeves and you be a good person,” she said. “You don’t hoard toilet paper — you give some to your neighbors and try to help them.”

Inside Section 60, Ami Neiberger-Miller placed pebbles on the gravestone of her brother, Army Spec. Christopher Neiberger, who was killed in Baghdad in 2007. She works with the Memorial Day Flowers Foundation, whose volunteers hand flowers to visitors to place on graves here on Memorial Day.

On Monday, they gave out 105,000 flowers, she said, fewer than the 240,000 of two years ago but up from 12,000 last year, when they used broomsticks to hand them out because of social distancing.

“Last year, I was more nervous,” she said. “There was somebody here who was trying to hug people.” Normally that was welcome, but in the throes of the pandemic “it freaked me out.”

Now, the hugs were back, and so was the hum of life that Neiberger-Miller loves. A man came with a 3-year-old and said, “Hey, Mark, I brought my son,” and pushed the child toward the stone. A man who brought a bottle of beer for his buddy tucked it beside the stone, and leaned in and whispered.

At one man’s grave, “I heard his widow telling his little nephews who will never meet him how to squeeze snapdragons to make them smile,” she said. “You hear all the beauty of life out here . . . There are tears, sometimes, but there’s also strength and beauty and laughter and so much hugs. There’s life here that you can see.”

Biden’s speech in Arlington was his second Memorial Day address for the weekend, a marker of how significant the holiday is to him. On Sunday, he attended a commemoration held near the Delaware Memorial Bridge in Wilmington, Del.

During Monday’s speech, Biden framed the central tension of the times as a battle between democracy and autocracy, calling it the “battle for our time.” He’s used this argument to push for his $4 trillion in proposed spending, saying Western democracies must show the world that they can make big investments and overcome gridlock.

But in this instance, Biden cited the importance of shoring up institutions.

“Folks, we all know it: Democracy thrives when the infrastructure of democracy is strong,” Biden said.

For Biden, the weekend has been personal, as well.

Biden’s older son, Beau, died six years ago Sunday. The president mentioned Beau, and his grief, during his public addresses Sunday and Monday.