[123]
Throughout 1849 and 1850, they contended with Narciso López, the Venezuelan radical who led repeated filibustering expeditions in an attempt to conquer the Spanish Captaincy General of Cuba. The annexation of Cuba was the object of fascination among many in the South, who saw in Cuba a potential new slave state, and López had several prominent Southern supporters.[124] López made generous offers to United States Armed Forces leaders to support him, but Taylor and Clayton saw the enterprise as illegal. They issued a blockade, and later, authorized a mass arrest of López and his fellows, although the group would eventually be acquitted.[125] They also confronted Spain, which had arrested several Americans on the charge of piracy, but the Spaniards eventually surrendered them to maintain good relations with the U.S.[126]
Arguably the Taylor administration's definitive accomplishment in foreign policy was the Clayton–Bulwer Treaty of 1850, regarding a proposed inter-oceanic canal through Central America. While the U.S. and Britain were on friendly terms, and the construction of such a canal was decades away from reality, the mere possibility put the two nations in an uneasy position.