LeRoy “Buster” Brown agreed to coach swimming at what is now St. Thomas Academy even though he did not know how to swim. Later he took on advocating for Catholic and other private schools at the Minnesota Capitol even though he was a newcomer to politics.

Brown, who went on to become a leading voice for private education in the state, did not shirk from daunting roles that required learning on the job. The longtime physics teacher was instrumental in integrating private school teams into the Minnesota State High School League and securing transportation and other public funding for these schools. Later, he set an example of remaining active and engaged beyond his 90s, surrendering his leadership posts in his parish finally at age 103.

Brown died in March. He was 105.

“He was much more than a physics teacher,” said Gerry Brown (no relation), a former student and fellow St. Thomas teacher. “He was a pioneer and a political activist — a legendary figure to us.”

LeRoy Brown grew up in Cumberland, Wis. He lost both his parents by age 17. The way the town rallied around him — he lived with his Boy Scouts troopmaster for a time — deeply influenced his belief in the importance of community and helping people, said his daughter, Mary LeClair.

Brown, who earned a master’s degree from the University of Minnesota, converted to Catholicism after meeting the woman who would be his wife of 64 years, Dorothy, a colleague at his first teaching job.

He often spoke of how Baraboo, Wis., public school officials confronted him about enrolling his daughter Margaret in a local Catholic school, threatening not to renew his contract in 1944. It was then that St. Thomas Military Academy, a Twin Cities Catholic prep school, recruited him to teach an elective physics class to seniors.

Gerry Brown said students loved the physics teacher’s self-deprecating humor and lively approach to his subject. Another former student, Joe Reymann, who also went on to teach at St. Thomas, recalls the one-on-one time LeRoy Brown gave him after classes to learn about his goals, hobbies and faith when he was a new student at the school.

When asked to coach the swim team, Brown protested he couldn’t swim but agreed to take the job and read a book to prepare. A tradition ensued: After winning a meet, team members threw Brown into the pool — and then jumped in to rescue him.

“It was such an honor for him to teach boys how to become young men,” said LeClair. “He really thought that was a privilege.”

Through the Minnesota Catholic Education Association, Brown started organizing state sports, debate and speech tournaments for Catholic-school students, later bringing in Lutheran and other private schools. In the late 1960s, he was tapped to head the education wing of the Minnesota Catholic Conference, turning to a former student for insights into lobbying.

He went on to co-found Citizens for Educational Freedom, which was instrumental in securing busing and some special education services for private schools, as well as tax credits and deductions for private school parents. He also successfully pushed for full Minnesota State High School League membership for private school teams.

Brown remained active long past his retirement. He continued to volunteer at St. Peter’s Church in Mendota Heights.

“He lived such a long life because he had a really positive attitude,” said Brown’s son, Charlie. “He treated people with respect, dignity and a sense of humor.”

In addition to son Charlie and daughters Mary LeClair and Margaret, Brown is survived by 10 grandchildren and five great-grandchildren. Services have been held.

Correction: Previous versions of this article had a headline that misstated the age of LeRoy Brown. He was 105.