Description: The Spanish American was fought when in 1898, Spain sunk the USS Maine in Cuba. This led to US intervention in the fight for Cuban independence. As a result of the war, the US established itself as a world power who now had possession of Guam, Puerto Rico, and the Philippines. Connection: After the Spanish American War, the US established itself as a imperial power with the territories it controlled and proved to the world their naval might by defeating Spain.
Lets get working on the canal!
Description: The treaty was developed in January 1919, and it ended WW1 by punishing Germany by making them repay the damages. The treaty was opposed by some members of the Congress because it would require the US to join the League of Nations which would mean that the US would have to deal with European affairs. Connection: The treaty showed that the US did not want to become involved with foreign affairs, but as they industrialized they were forced to imperialize which led to the US having to deal with foreign affairs.
Open Door Policy
Description: U-Boats were used by Germany in WW1, and it sunk many ships because it could move underwater undetected. When Germany started sinking ships with unarmed US passengers, the US broke off diplomatic relationships with Germany, and entered the war in 1917. Connection: U-Boats led to US participation in WW1 which led to a necessity of an increase of production and manufacturing. The US emerged as a world industrial leader that was capable of accomplishing things such as the construction of the Panama Canal.
Look at our naval might! No country can stop us.
Description: The canal was created in 1914 and it connected the Pacific and Atlantic Oceans which drastically reduced the time it took to trade with countries across the oceans. The construction was led by Theodore Roosevelt, and it showed the might of US when other countries couldn't create the canal. Connection: The construction of the canal led to a booming economy in the US, and increased trade with countries in Asia like China. The Open Door Policy became important to the US so that they could keep trading with China with the Panama Canal.
Description: In 1899 John Hay proposed the Open Door Policy to allow everyone to trade with China by having its ports open to all. This would not allow a nation to have a sphere of influence in China which would most likely not allow the US to trade with China. Connection: After the Spanish American War, the US began to take part in foreign affairs like this one where John Hay took action to keep trading with China which helped American businessmen and America's economy.
Description: Imperialism was a country expanding its influence to other countries and the world. When the US established itself as a powerful nation in the world, the US were forced into world conflicts. Connection: Imperialism was an age where the US finally changed their stance on being an isolationist country. After being established as an imperial power, the US began to take part in foreign activities that would change America's economy forever. Without imperialism the US wouldn't be industrialized or culturally diverse as it is today.