This would generally be about the 15th year of their age
I find it interesting that the Board of Commissioners believed that kids at the age of 15 are ready to attend the university. Today, kids at the age of 15 are beginning high school and are far from ready to go to college. However, the lifespan in 1818 was much different than it is today and the country needed young scholars to be ready to take on the challenges of the country as soon as it was possible.