To many people who grew up in Southeastern Massachusetts, and even beyond, late August means it’s time for the Marshfield Fair.

This is the 150th anniversary of the fair, and organizers have planned many special events to mark the occasion.

Running for 10 days through Sunday, Aug. 27, the fair includes traditional rides, food, entertainment, agricultural and horticultural displays, and animal exhibits. Historical demonstrations, as well as a parade and an expected visit by Governor Charlie Baker, help celebrate the anniversary.

The fair owes its rich history to farmers from Marshfield and the surrounding areas who first gathered for a social outing during the harvest season in 1862. They brought their livestock and shared meals with families using the abundance of produce from the growing season.

In 1867, those organizers officially incorporated as the Marshfield Agricultural and Horticultural Society, which to this day has run the Marshfield Fair.

The organization’s current president, Leonard LaForest, said those forefathers would hardly recognize the fair today.

“I think it would scare the hell out of them,’’ he said recently, with a hearty chuckle.

The annual fair has had a long run, but it’s far from being the nation’s oldest — although that title seems to be in question.

The Knox County Fair in Bicknell, Ind., founded in 1809, may be the “oldest county fair in the United States,’’ its website states. The Jefferson County Fair in Watertown, N.Y., incorporated in 1817, says it is “the longest consecutively running fair in the USA.’’

Then there’s the Steuben County Fair, in Bath, N.Y., which contends it is “the oldest continually running fair in the United States.’’ It originated in 1819.

In Massachusetts, the Three County Fair in Northampton was established in 1818. The Topsfield Fair is celebrating its 200th fair this year, having first organized in 1818. Its website also asserts it’s “the longest continuously operating county fair in America,’’ drawing nearly 500,000 people last year.

The Eastern States Exposition in West Springfield – The Big E – is a relative youngster, established in 1917. More than 1 million people visited the fair during its 17 days last year.

LaForest said the Marshfield Fair compares itself in attendance with the Barnstable County Fair in East Falmouth, first held in 1844, as well as Topsfield.

As the industrial revolution’s advances changed life for Americans in the 1800s, these fairs were organized to promote agriculture and share ideas of modern farming.

The first years of the Marshfield Fair were held on a small field near the current fairgrounds. A train running from Boston brought visitors to the exhibits. The train stopped running in the 1940s, according to LaForest.

As the fair grew in size, activities, and popularity, the nonprofit society accumulated more land through bequeaths and purchases. The fairgrounds, situated along Route 3A, now measure about 67 acres.

Horse racing became a major attraction. Later, carnival rides were a draw for families.

Horse racing ended in 1991. LaForest said the decision to drop racing came after the state racing commission wanted to move the races to September to avoid interference with other racing venues.

“We couldn’t have our fair in August and then have racing in September,’’ LaForest said.

It was a tough decision, but society members felt eliminating racing was for the best.

“It made us reinvent ourselves, which in retrospect was a great thing,’’ said LaForest. “After the racing [ended], everybody thought we were going to just disappear, dissolve. And we wound up using just about all our funds and we wound up being able to come back. And within about five years, we were in the black, and we haven’t stopped since.’’

Part of the reinvention includes educational workshops, farmer’s markets, and special events held throughout the year. More recently, the fairgrounds have hosted music festivals.

True to the first organizers’ wishes, the society continues to promote education. To teach history, it opened a museum at the fair, featuring antique farming equipment, photographs, and other memorabilia.

The fair itself also provides an opportunity for underprivileged children and those from urban areas to learn about agriculture. “They get to see chickens and lambs and sheep and pigs. They wouldn’t have the opportunity to see that,’’ LaForest said.

This year, patients from a local memory care facility, as well as children from Cardinal Cushing School with sensory challenges, will attend the fair for free before the gates open to the general public on Aug. 23.

Nearly 150 members support the society’s efforts, and its office on Main Street is a busy place leading up to opening day.

The fair is fully self-funded, according to the society’s secretary/treasurer, Carleton Chandler. While working on this year’s big event, he and other directors are also looking to the future, to ensure the society remains financially successful and viable.

“One of the difficulties we’re running into now is we’re all getting old,’’ Chandler said of many of the society’s directors. He and LaForest are both 70, classmates from the Marshfield High School class of 1965.

“It’s tough to be able to find young people that are interested [in becoming directors], and secondly to find young people who have time,’’ he said.

The fair drew about 160,000 people last year, according to Janet Scribner, a younger society director who helps make sure the fair runs smoothly.

“I guess at this point, we’re just making sure we run the best show we can,’’ Chandler said. “You hope that after the 10 days are done, if you spend $100, you hope you took in $101. That’s pretty much what it comes down to.’’

LaForest and Chandler have worked for the society for 40 years. But they have been involved with the fair nearly all their lives, because their fathers were also society directors. The two have many fond memories of the fair over the years.

“I think as a kid, just like any other kid, you look to see the lights and the rides. And you want to try to do everything and eat yourself sick,’’ LaForest said.

Chandler’s memories are of family gatherings to view the horse racing from car tailgates.

“It was only fair racing, but it was a little different clientele. A lot of people would rent houses for the week, so they’d bring the families to the beach. The kids and wife would go to the beach. And some would go to the races. And everybody was happy. You got the best of both worlds,’’ Chandler said.

“And so it has evolved. But the concept of the fair hasn’t evolved at all. It’s still promoting agriculture.’’

The fair is open noon to 10 p.m. Admission into the fairgrounds, at 140 Main St., is $10, and children age 6 and under are admitted free. Visit www.marshfieldfair.org for more information.

Ferrari can be reached at kkferrari219@gmail.com.