BRISTOL, R.I.—In July 1785, the citizens of this waterfront town assembled to heap praise on their newly minted nation and to thank God for helping them survive a fierce assault by the British during the Revolutionary War.

In July 1892, lawyer Orrin Bosworth preached that the townsfolk should be accepting of the immigrants arriving en masse: “America has no cause to fear the lover of freedom, be he American or foreign born.”

And in July 1963, judge Arthur Carrellas roared to the citizenry about the U.S. Supreme Court’s decision to ban Bible readings in public schools.

Prayer, speeches and other such “patriotic exercises” have marked the Fourth of July in Bristol every year since 1785—allowing the town to lay claim to the nation’s oldest Independence Day celebration.

Over the years, the speeches—given by judges, senators, war veterans and others—have run the gamut from typical exhortations of patriotism to muscle-flexing against Communist countries to criticism of court decisions.

The patrotic exercises and annual parade that follows are institutions in Bristol, where pride in country is manifest in the red-white-and-blue center stripe that runs through the main artery of the town and in the American flags and banners that hang outside restored colonial homes.

The parade has continued uninterrupted with the exception of a few years—such as 1881, when President James Garfield was shot. Some events—like chasing a greased pig around the Common—have been abandoned, but modern-day fixtures include a concert series, orange crate derby, nighttime ball, a Miss (and Little Miss) Fourth of July pageant—even a contest recognizing the person who has traveled the farthest.

“Sometimes we think we have red, white and blue running through our bloodstream because of our commitment to the celebration,” said parade chairwoman Judy Squires, a lifelong Bristol resident and part of a committee of 110 volunteers that runs the event.

The festivities draw about 100,000 people, including some from far outside Rhode Island, Squires said.

William Holmes, 54, said he’s surprised by other communities that celebrate Independence Day in a nonchalant way.

“To Bristolians, it has the same impact as Christmas,” said Holmes, an administrator at the Ethan Allen furniture company who was cleaning the exterior of his home near the parade route last week in preparation of the event. “Everyone is celebrating outside, backyard to backyard.”

The first July Fourth observance was organized by the Rev. Henry Wight in the town Congregational church. It initially consisted of prayers and orations. The annual parade began some years after that—and likely by accident as people walked in clusters to the meeting house for services, said Richard Simpson, an unofficial parade historian and author of “Independence Day: How the Day is Celebrated in Bristol, Rhode Island.”

“You can do away with the parade, but you can’t do away with the exercises,” said Simpson.

The patriotic speaker this Saturday will be Edward Cyr, a nurse anesthetist from Bristol and retired Army reservist who has been deployed in recent years to Iraq and Kosovo. He said his speech would focus on a shared obligation to the country.