HAMILTON — Under clear blue skies, with an American flag waving high, the ninth annual Military Service Day was held here Saturday at the Patton Homestead, the historic estate of the late World War II hero General George S. Patton.

The day this year honored the late Joanne Holbrook Patton, a well-known advocate for military families, those with disabilities, and others in need, who gifted the 27-acre estate to the town more than a decade ago. The generous gift opened up acres of lush green land and horse trails for public use and enjoyment.

“Time is the most precious thing that we all have, and we don’t have that much of it,’’ said her son Ben Patton, 58, speaking during a ceremony dedicating the day in her honor. “My mom gave all of it.’’

Holbrook Patton died last September at age 92, leaving her own legacy of service, helping those in need, advocating for social services for military families and people with disabilities. Her late son, George, competed in the Special Olympics as an equestrian.

She was married to Major General George Smith Patton IV, son of the iconic war general, whose wife, Beatrice, lived at the estate during World War II.

Family, friends, historians, and veterans gathered Saturday for a service day that recalled Holbrook Patton’s many contributions, most notably the gift of her family’s estate to the public.

Patriotic tunes played loudly from speakers as people, some wearing hats adorned with military pins and others dressed in American flag clothing, strolled across the land in the warm sun.

“You can look out here and see these kinds of waves and undulations, and you can think of my mother,’’ said Ben Patton, the youngest of Holbrook Patton’s five children and a filmmaker who leads workshops for veterans.

Vintage military vehicles were spread across the fields. A State Police helicopter landed. The National Lancers, a mounted horse cavalry unit, participated, along with Revolutionary War reenactors.

Donna Watkins, 77, traveled from Colorado with her husband, Charley, 80, who served under the command of Holbrook Patton’s husband during the Vietnam War. They remained close friends ever since.

“I miss my dear friend,’’ Donna Watkins said, her eyes moist.

Cheryl Poppe, who served three decades in the Army National Guard, recalled Holbrook Patton’s support for her military career. “Her example teaches us that all of us can act and create . . . positive change,’’ she said.

The military service day first started as a small event on the lawn of the Wenham Museum. Holbrook Patton, who lived at the Hamilton estate for decades after her husband’s retirement, offered one year to have it at their home, which once operated a farm called Green Meadows.

The invitation morphed the event into a celebration that now draws thousands, organizer Ernie Stone said.

“This event will forever be sort of a dedication to her,’’ he said.

Food trucks served everything from lobster rolls to tacos. Children played in the fields. Holbrook Patton’s daughter Helen Patton said that she hopes the day prompts people to think about the care of her mother’s cherished land that now is owned by the town.

The main house is a community resource center, which includes access to the Patton archives. A portion of the land was redeveloped for affordable housing, but most of it remains open land.

Funds are being raised to build a pavilion dedicated to Holbrook Patton on the estate, which currently has no outdoor shelter.

Helen Patton said that the family is hopeful the town will always keep the estate in good stead. “We’re confident they would never sell it or let it turn into rocks,’’ she said.

Like her mother, she is active in military social services, with a focus on creating memorials for families in Europe. “I will always be learning from her,’’ Helen Patton said.

Shannon Larson can be reached at shannon.larson@globe.com.