American intelligence agents infiltrated a Spanish spy ring operating in Montreal during the Spanish-American War. Here's What You Need to Know: By the end of the 19th century, the United States had grown into one of the major players on the international stage. Americans had tamed a continent from the Atlantic to the Pacific, and the mighty industrial engine of the country was making the nation increasingly self-sufficient and self-confident as it looked across the oceans toward the rest of the world. In 1898 the United States rushed into war with Spain, which leaders in Washington saw as continuing to interfere in Cuba and other parts of Latin America. In hindsight, the Spanish-American War might have been avoided except for the jingoistic American press, which was clamoring for hostilities to start in the wake of the mysterious sinking of the USS