The two pictures below come from the School Committee's Report in 1899 and features a list of the ten graduating seniors. The students were on different "courses" (Classical, Latin Scientific, and English) which allowed them to take classes based on what they hoped to do in the future. For example, the two students on the Classical Course likely aimed to attend a college where they could study Literature or History.
Since the graduating class was so small, it's hard to determine if these three courses were the only three. Two of the courses, Classical and English, seemed appropriate for future scholars or educators, while the Latin Scientific Course was best fit for future doctors, researchers, and types of specialized scientists.
Some high schools have systems like this today where students can tailor their schedules to suit their interests. While most schools try to give students well-rounded educations on a variety of topics, more specialized tracks give students an in-depth education in a subject they enjoy.