The grass below the Soldiers and Sailors Monument on Boston Common became a sea of red, white, and blue Thursday morning, marking the ninth year the flag garden has been created for Memorial Day.

An American flag is placed in honor of every Massachusetts hero who has fallen since the Revolutionary War. More than 37,000 flags waved in the air this year.

To Joe Cook, who lost his 28-year-old son, Timothy, after he fought in Iraq, the flags represent freedom.

“It’s freedom, and it’s remembering the spirit of those who fought for our country,’’ said Cook, who lives in South Boston. “It’s very touching and very inclusive.’’

This year, the names of the 296 military men and women who died in or as a result of the Iraq or Afghanistan wars were read aloud as the last of the flags was placed in the garden, which was put together by more than 700 volunteers Wednesday.

One by one, family members stepped up to the podium, reading the names of lost loved ones, as well as names of other soldiers who died.

“It’s hard to read his name, but he would want me to be here,’’ said Betty Crawford, 65, of Beverly, who lost her son in Afghanistan in 2008, when he was 25 years old.

Her son, Stephen Fortunato, was a specialist in the Army, and on Thursday, Crawford pinned a yellow rose to her chest to remember him.

“It’s so moving to see all those flags representing the Massachusetts fallen heroes,’’ she said. “Every time you look at a flag you think of your son, because he fought for that flag.’’

Mayor Martin J. Walsh, Governor Charlie Baker, Lieutenant Governor Karyn Polito, and Attorney General Maura Healey joined the families at Thursday’s ceremony, which was organized by the Massachusetts Military Heroes Fund.

“People talk all the time about the life people lead before somebody dies, and the life they lead after . . . The families representing these thousands of flags behind me who lost someone — for them, it’s a daily personal struggle to not only put the pieces back together, but to find some way to create positivity and purpose despite the empty chair at the table,’’ Baker said to the crowd.

Lynn resident Dorris Syrakos and her family attended the ceremony for her son, Antonio, who died when he was 22 in Afghanistan.

“Freedom is not free,’’ Syrakos said. “We want all civilians to remember that. We feel hurt and pain every day of our lives . . . It was a horrendous loss, but coming and seeing the flags reminds us that none of the soldiers are going to be forgotten.’’

Irene Richards, 60, of Ashland, was thinking of her daughter, Deanna, during the event. She wore a pin with Deanna’s face on it Thursday.

“The flags mean a lot to me,’’ Richards said. “It’s a special day, but Memorial Day is every day. We’ll never forget about how they sacrificed their lives.’’

The Massachusetts flag garden — made up of 37,268 flags — has inspired similar tributes to fallen soldiers nationwide, including in Texas, Ohio, and Louisiana, and in Canada in Toronto, according to a statement from the military fund.

“Today’s event is unique and very special,’’ Walsh said. “It fills us with awe every single year. . . . [The flags] bring into view something that’s too often invisible — the sea of sacrifice that underpins our nation’s way of life.’’

Elise Takahama can be reached at elise.takahama@globe.com. Follow her on Twitter @elisetakahama.