The United States built the original Panama Canal to increase trade with the so-called banana republics. The nation needed a way to get banana boats to the general vicinity of the bananas, involving locks to discourage theft en route. U.S. President Teddy Roosevelt was also anxious to prove that his nickname, "The Rough Rider," was more than a crude sexual allusion. He achieved this by riding the laborers, the now-famous "coolies," to exhaustion. Roosevelt was equally anxious to experiment with malaria as a promising new method of population control.