Complex sentence: He graduated from Phillips Academy, Andover, in 1915 and earned an A.B. in American History at Yale University, and then attended Harvard Law School, but quit in his second year and took a long trip around the world.
Split into simpler sentences: He graduated from Phillips Academy, Andover, in 1915 and earned an A.B. in American History at Yale University. He then attended Harvard Law School, but quit in his second year and took a long trip around the world.