have they competed in any national or international level competitions?
Yes, Mid-Atlantic Prep League.
Blair Academy
Blair primarily competes in the Mid-Atlantic Prep League (which includes Blair Academy, The Peddie School, The Lawrenceville School, The Hill School, Hun School of Princeton and Mercersburg Academy).
who is  finn m. w. caspersen? American financier and philanthropist. where did he study? Peddie School, Brown University, and Harvard Law School. which all sports were entertained in the first one ? Football, Basketball, Tennis, swimming, etc. who are their rivals in the first one? Blair Academy where is it located? Blairstown Township, New Jersey. what facilities do they provide? Bogle Science Center provides laboratories and classrooms, and includes the 100-seat Cowan Auditorium.
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Blair Academy [SEP] Athletics
Blair primarily competes in the Mid-Atlantic Prep League (which includes Blair Academy, The Peddie School, The Lawrenceville School, The Hill School, Hun School of Princeton and Mercersburg Academy). Its traditional mascot is the "Buccaneer" (with the team called the Bucs) and the school colors are navy blue, white and grey. Blair's traditional arch-rival is The Peddie School of Hightstown, New Jersey. Since 1903, Blair and Peddie have competed in football, and the rivalry constitutes New Jersey's oldest continuous prep football competition. Each November, the two schools vie for the coveted Kelley-Potter Cup by playing against one another in a fall sports competition.