WEST CLAREMONT — Two hundred years ago, Virgil Barber decided to build a church down the street from where his father had been a pastor.

This wouldn’t be unusual, except that Virgil Barber built a Catholic church and the one his father, Daniel Barber, had led was the Union Episcopal Church, which is now known as New Hampshire’s “oldest standing Episcopal church,” according to its historic marker. Virgil himself had been an Episcopal minister before both father and son converted to Catholicism after questioning their Protestant faith.

After converting, Virgil Barber began building what is now Old St. Mary next to his family’s home in Claremont.

The story of what is now New Hampshire’s oldest Roman Catholic church, Old St. Mary, is a family story: Of the questioning of faith that the family that founded it experienced, as well as of the church family that has cared for the simple brick structure for two centuries, never letting it fall too far into disrepair.

“It’s an amazing history. Amazing,” Claire Lessard, who has been a parishioner since 1941, said during an interview last month at Old St. Mary on Old Church Road. “There’s just so much history we’re so thankful for. How many people have been fortunate to be in a parish with all this history? Every parish has history, but this one is special.”

People of all religious affiliations are welcome to join in the celebration of Old St. Mary’s 200th anniversary this year. Guided tours of the church will be held after 9 a.m. Mass Tuesday and after 5:30 p.m. Mass Wednesday and Thursday. The Most Rev. Peter Libasci, Bishop of the Diocese of Manchester, will lead Mass at St. Mary’s Central Street location at 10:30 a.m.; following the Mass, there will be a parish picnic and barbecue.

At the time of Virgil Barber’s conversion to Catholicism, he was married to his wife, Jerusha, and the couple had five children, said Steve Denis, a long-time parishioner who, along with Lessard, has spent decades researching the history of St. Mary.

But Barber did not just want to be a Catholic: He wanted to be a Catholic priest. In order to do so, he and Jerusha had to legally separate in the eyes of the church.

“When they separated, at one point it became worldwide in the Catholic Church about this family and how they came from Episcopalism,” Denis said during an interview at Old St. Mary last month.

Jerusha Barber became a nun; their children — the youngest was 10 months old — were taken in and raised by members of the Catholic church.

“They never really saw each other as a family unit again,” Denis said.

According to research Denis has conducted, when questioned about giving up her children, Jerusha Barber replied, “ ‘They’re my children, but they’re really not. They’re God’s.’ ”

“That’s faith,” Denis said.

After becoming ordained as a Jesuit priest in 1822, Virgil Barber got to work building New Hampshire’s first Catholic Church in Claremont, which was attached to his family home. (The house is no longer standing.) He also opened the first Catholic high school in New England, known as the Claremont Catholic Seminary, on the upper floors of the church.

“It was only very short-lived,” Denis said.

In 1827, Virgil Barber was called to Georgetown. The Claremont school closed, but the Catholic community Barber built continued.

“Once in a while, a priest would travel many miles and come and say Mass,” Lessard said. “It was very rare.”

The community still met for prayer when there was not a visiting priest there, Denis said. Though it’s the oldest church in the state, Old St. Mary is not the oldest parish in New Hampshire because there was a brief period of time when there was not a pastor assigned to it.

St. Mary was considered an official parish in 1870 and they built another church on Central Street, which was dedicated in 1875, said Tara Bishop, communications director for the Diocese of Manchester. The first parish in New Hampshire was St. Aloyisius in Dover, which was established in 1830.

Old St. Mary was regularly used until 1866, according to a history posted to St. Mary’s website. Even though St. Mary’s Central Street church became its primary location, Old St. Mary was never abandoned.

“I think what amazes me is the dedication of the parishioners,” Mark Roberts, chair of pastoral council and chair of 200th anniversary celebration, said during a tour last month at Old St. Mary. “When you look at it and you think 200 years ago, this was a bustling place … and here it is 200 years later.”

There are even the wooden desks that the students sat at when Virgil Barber’s school was in session. The original hardwood floors are still intact. Sunlight streams through simple glass-paneled windows. On the third floor of the church, Denis stopped to point out original windows.

“The irregularities were not uncommon in glass during that time,” he said.

Over the centuries, heat and electricity were added to the church. The pews were upgraded and the Knights of Columbus devoted money to its upkeep, including a renovation that was completed in 1965. On Saturday mornings from late May to Columbus Day, Mass is held at Old St. Mary. Weddings and funerals also take place at the church.

Stained glass windows were never added to the brick structure, and the alter is relatively simple. On a sunny day, its white walls and large windows make the inside glow.

“It’s so restful and peaceful,” Bishop, the diocese’s communications director, said. “You feel the Holy Spirit here.”

Outside, there is a memorial for Virgil Barber, who was buried at Georgetown after he died in 1847. The surrounding cemetery is split into two: one for Catholics and one for Episcopalians.

St. Mary’s, like other churches in Claremont, has played an important role in the city’s history. In addition to being places of prayer, they were also places of community — especially as more people immigrated to Claremont to work in the mills. Today, those parishes are still active and volunteer for various community organizations.

“It is our faith; it is our belief that we are the hands, feet and lips of Jesus continuing what He did over 2,000 years ago, i.e., bringing love, healing and forgiveness to those in need,” Denis wrote in a follow-up email. “Thus the members of all local churches who live out the faith they profess on Sunday and every day continue to have a positive impact on the Claremont community in which we live, work and play.”

For more information about Old St. Mary and the 200th anniversary events, visit stmaryparishnh.org. Liz Sauchelli can be reached at esauchelli@vnews.com or 603-727-3221.