Spain was concerned, there was a nationalist agitation, in which the written press had a key influence, causing the Spanish government to not give in and abandon Cuba as it had abandoned Spanish Florida when faced with a troublesome colonial situation there, transferring it to the U.S. in 1821 in exchange for payment of Spanish debts. If the Spanish government had transferred Cuba it would have been seen as a betrayal by a part of Spanish society and there would probably have been a new revolution. So the government preferred to wage a lost war beforehand, rather than risk a revolution, opting for a "controlled demolition" to preserve the Restoration Regime. On April 20, 1898, McKinley signed a joint Congressional resolution demanding Spanish withdrawal and authorizing the President to use military force to help Cuba gain independence. In response, Spain severed diplomatic relations with the United States on April 21. On the same day, the United States Navy began a blockade of Cuba. Both sides declared war; neither had allies. The 10-week war was fought in both the Caribbean and the Pacific. As United States agitators for war well knew, United States naval power would prove decisive, allowing expeditionary forces to disembark in Cuba against a Spanish garrison already facing nationwide Cuban insurgent attacks and further devastated by yellow fever. The invaders obtained the surrender of Santiago de Cuba and Manila despite the good performance of some Spanish infantry units, and fierce fighting for positions such as El Caney and San Juan Hill. Madrid sued for peace after two Spanish squadrons were sunk in the battles of Santiago de Cuba and Manila Bay, and a third, more modern fleet was recalled home to protect the Spanish coasts. The war ended with the 1898 Treaty of Paris, negotiated on terms favorable to the United States. The treaty ceded ownership of Puerto Rico, Guam, and the Philippine islands from Spain to the United States and granted the United States temporary control of Cuba. The cession of the Philippines involved payment of $20 million ($ million today) to Spain by the U.S. to cover infrastructure owned by Spain. The Spanish-American War brought an end to almost four centuries of Spanish presence in the Americas, Asia, and the Pacific. The defeat and loss of the Spanish Empire's last remnants was a profound shock to Spain's national psyche and provoked a thorough philosophical and artistic