Problems with declining enrollment in the late 1960’s concerned the leaders of Pio Nono, Don Bosco and the Archdiocese. Eventually, strong feelings of tradition gave way to the cold reality of economics. Over a century had passed since Pio Nono first had been founded when the merger of the two schools was announced. In 1972 a “new” school was to emerge from these respected institutions. Named after the former Lord Chancellor of England, who became a martyr, Thomas More High School began a new era based on blending the uniqueness of two fine traditions. Bro. Dan Sharpe, S.M., who had been principal at Don Bosco, was named the first principal of Thomas More High School.
After surviving the trials of the first few years of the merger, Thomas More established itself as a leader in the educational preparation of young men and was also known for its fine extra-curricular programs. While the achievement statistics were excellent, other indicators were disturbing. Gradually increasing costs and declining enrollment over the next 15 years eventually led to serious discussions about the future. Another issue of concern was the loss of the services of the Marianists in 1987. Due to a decline in personnel available to staff schools, the order felt compelled to focus on staffing other schools which they founded and sponsored.
A newly-established Board of Directors commissioned a study to investigate population trends in the area and educational needs of community families. From this research, the Board determined the people of this area wanted a co-educational school. After much deliberation and communication with administrators of other schools, a request was issued to become a co-ed school. In 1989, under Archbishop Rembert Weakland’s direction, Thomas More welcomed its first female students. In 1992, full enrollment of 750 students was reached, and was sustained at that level for many years before a slow trend of declining enrollment ensued in the early 2000s.