Lopez at once began actively to outline his plans for a revolution, and secret headquarters were established at Cienfuegos, while the organization was extended to other parts of the island.
Lopez planned to begin the uprising for the freedom of Cuba on June 24, 1848. He had enlisted the sympathy and secret cooperation of many men in the United States, chiefly in the southern part of that country, and looked to them to provide him with the needed arms and ammunition. There was no lack of readiness on their part to respond to his needs in this respect, but there was much difficulty in transporting such supplies from the United States to Cuba. Whatever the personal sentiments of the officers of the American government, they were required publicly to do all in their power to prevent illicit traffic; while of course the Spanish officials in Cuba were vigilant to prevent the landing of any such cargoes. The result was that sufficient supplies did not reach Cuba in time for an uprising on the appointed date.
The delay was fatal. It afforded opportunity for betrayal. Among the followers of Lopez in Cuba was one José Sanchez Yznaga, a mere lad of tender years. He could not resist the temptation to boast to his mother of the great enterprise in which he was to take part, and she, drawing from him all the details of the conspiracy, repeated the story to her husband. Forthwith he gave information of it to the authorities; reputedly in order to prevent his son from getting into mischief. Lopez, unconscious of what had happened, was "invited" by the Governor of Cienfuegos to call upon him, on a matter of important business, and was actually on his way to keep the engagement when he learned of the betrayal. Instantly he changed his course, and instead of going to Cienfuegos he took train for Cardenas and thence a coasting vessel for Matanzas. At the latter port he was so fortunate as to find the steamer _Neptune_ just starting for New York. She had room for another passenger and he got aboard without detection by the Spanish officers who were in quest of him. The boy Yznaga also escaped arrest. Apparently the names of the other conspirators were not disclosed, or else there was no convincing evidence against them. At any rate, none of them were imprisoned or punished in any way. But Lopez himself was tried _in absentia_ and was condemned to death, on March 2, 1849; and Yznaga, also absent, was condemned to six years' imprisonment.