Once arrived López began planning a filibustering expedition from the United States to liberate Cuba. He made contact with influential American politicians, including John L. O'Sullivan, an expansionist who coined the term "manifest destiny." López recruited Cuban exiles in New York City and other adventurers to his cause, and in 1849, his expedition was poised to embark: a troop of 600 volunteers had gathered on Round Island, Mississippi, with three ships chartered (two in New York and one in New Orleans) to transport them. However, US President Zachary Taylor, who had renounced filibustering as a valid means of US expansion, took steps against López and ordered his ships to be blockaded and seized. By September 9, the "roughnecks" had all been talked into leaving Round Island.