The Southern diplomats who in this remarkable document threatened forcible con quest of Cuba if Spain refused to sell the island to the United 154 THE SOUTH AND THE MYTH States, were trying to put into effect a geopolitical conception developed in part from the general notion of manifest destiny and in part from the idea of the passage to India. The oceanographer Mathew F. Maury, leading Southern scientist of his day, had called the Gulf of Mexico the American Mediterranean. Into this sea emptied the Mississippi, and the archaic Southern tendency to emphasize the primacy of natural waterways allowed Southern thinkers to conceive of the Gulf as dominating the whole interior valley. On the east the Gulf merged into the Caribbean, which touched the Isthmus of Panama, gateway to the Pacific; control of the Gulf was said to mean mastery of the dominant commercial route to the Indies. Southward the Caribbean led to South America, where the slave empire of Brazil in the fabulous basin of the Amazon offered the world's most promising theater for expansion of the plantation system.27 The key to all this potential empire was Cuba: ". . . if we hold Cuba," wrote an editorialist in the Richmond Enquirer, "in the next fifty years we will hold the destiny of the richest and most increased commerce that ever dazzled the cupidity of man. And with that commerce we can control the power of the world. Give us this and we can make the public opinion of the world." 28