As Holy Spirit School in East Greenbush celebrates its 50th anniversary year, community members are reflecting on a history marked by big changes, uncertainty and resilience.

The Franciscan Missionaries of the Divine Motherhood of England opened Holy Spirit School in 1962 to teach kindergarten through fourth grade.

The school grew to include fifth and sixth grade, followed by seventh and eighth, though the middle grades later ceased. Three nuns served as principals and 15 taught; the order left the school in 1981.

In the late 1980s, enrollment plummeted to 85 students, causing concerns about Holy Spirit's future. Enrollment stabilized when Sister Maureen Moffitt, CSJ, took over as principal; she added a middle school building in the early 2000s, as well as a computer lab and library.

Enrollment for the upcoming school year is at 170 students from pre-kindergarten through eighth grade, plus 90 children in day care. The early childhood programs recently shifted from two days a week to five, with longer hours. The daycare program has a two-year waiting list.

This year, the computer lab will be moved and upgraded, teachers will receive new laptops and the gym will be painted.

"The Holy Spirit School community is fantastic, and now I know what it's built on," said Anne Cowling, who's just entering her second year as principal.

She looks forward to adding more classrooms and celebrating the anniversary; events include a dinner with Bishop Howard J. Hubbard and an alumni basketball tournament.

"Basketball is king here," Ms. Cowling noted: Teams start in the third grade.

Maryann McConnell is about to start her 22nd year at Holy Spirit as a kindergarten teacher. She said daily prayer and inter-grade activities make the school special.

"We care deeply about the children," she said. "The day they graduate from kindergarten is as special to me as the day they graduate from eighth grade. Everybody in the school knows the kindergarten class probably by the end of the first month."

Mary Cooper, who taught at Holy Spirit for 14 years until her retirement in 1990, agreed.

"It was just always so open, so friendly," said Mrs. Cooper, whose five children and three grandchildren are graduates; five grandchildren are attending now. "They made you part of things. They always knew you."

Some Ballston Spa residents say that St. Mary's School is a well-kept local secret, but there was nothing secret about the school's 50th anniversary celebration in June: The mayor attended the party and declared it "St. Mary's School Day" in the village.

In September, the school will welcome back 210 students from kindergarten to fifth grade.

Construction over the last decade doubled the size of the school to include a library, more classrooms, a prayer corner, a 90-seat theater and more. Every classroom now features interactive, internet-ready boards, and 50 laptops are available for student use.

The after-school robotics program grew from two teams to five teams last year, and other enrichment programs are gaining in popularity.

Test scores are improving, and more parents of students with special needs are choosing the school, which offers small-group instruction and learning centers for these children. Intervention services for kindergartners and first graders who exhibit learning problems are next on the list.

"We have a little gem," boasted Mary Arnold, whose daughter, Schuyler, graduated from St. Mary's last spring. "I think it kind of goes under the radar."

With help from her kindergarten teacher, Schuyler had grown from a shy three-year-old into an involved student, donating hats and gloves to needy children at Christmas and participating in other service projects as she grew older.

Mrs. Arnold said the teachers' "everyday actions really instill values in these kids." In fact, Schuyler still attends the First Communions of younger students: "They understand it's important."

Five Sisters of Mercy taught 245 students when St. Mary's School opened in 1960; the order stayed until 1987. The Sisters of St. Joseph of Carondelet have also maintained a religious presence as teachers and administrators.

The school included sixth, seventh and eighth grades at various points; the sixth grade was incorporated into a seven-year program at Saratoga Central Catholic High School in 2006.

Michele Lezon, principal, said the new Global Foundries semiconductor fabrication plant in Malta will likely attract more families, but she expects the school to stay small.

Its slogan, after all, is "a small school with a big heart."

"You walk in and you feel warm," Mrs. Arnold confirmed.

Gail King, a librarian at the school for 10 years and previously a teacher for 13, noted that "there's nothing that I like better than to see children I taught in the classrooms sending their children to St. Mary's,"

Ms. Lezon feels St. Mary's will be around for a long time. Though she's only entering her third year as principal, she said the school's anniversary celebration was "like being at a family reunion. It's good, in this digital age, to know that there's still a flesh-and-bone family."