When the four students — Alonso Sanchez, Love Johnson, Leah Armstrong and Caterina Lombardi — set out in October for the Universidad de las Americas in Puebla, Mexico, they made history: They were the first to “graduate” from the “think tank” called the American Airlines Leadership of the Americas — which will gather for at least two more years the top student minds from nine universities in nine countries. For the past year, the TCU delegation came together with other participants in person and over the Internet to discuss challenges common to all countries in the Western Hemisphere.