Final answer:
Between 1788-1865, the United States faced foreign issues such as the War of 1812, the Mexican-American War, and the Monroe Doctrine, with the War of 1812 and the Mexican-American War being conflicts against Britain and Mexico respectively, while the Monroe Doctrine established U.S. policy toward European intervention in the Americas.
Step-by-step explanation:
Foreign Issues in the United States (1788-1865)
The three foreign issues that the United States dealt with between 1788 and 1865 were the War of 1812, the Mexican-American War, and the Monroe Doctrine. The War of 1812 was a significant conflict against Great Britain which arose from unresolved tensions, including the British practice of impressment of American sailors. The Mexican-American War was fought over territorial disputes after the U.S. annexation of Texas, and it led to the U.S. acquiring vast southwestern lands. The Monroe Doctrine was a foreign policy statement that aimed to prevent European intervention in the Western Hemisphere, thereby asserting U.S. influence in the region.
The Louisiana Purchase was a significant event as well, but it was a peaceful acquisition of territory from France in 1803 that more than doubled the size of the United States. Although it did raise questions related to the expansion of slavery, it was not a conflict with a foreign power. On the other hand, the Civil War was an internal conflict and does not qualify as a foreign issue.