The Spanish American War was started mostly because of the sinking of the USS Maine. The Spanish American War was mostly because of Cuba fighting for independence, the US supported these revolutions. The US also was also fought for control of the Panama Canal, which the US gained control of.
The causes for Imperialism are wanting expansion for their country. Imperialism is for economic reasons, to expand religion , and for political reasons. Imperialism is a country seeking to expand a country's power, military power, and land.
The Open-door policy is referring to the US opening trade with China. The US opened trade in China and was a big step in the US' economy. This policy is to allow all trade equally within nations, and was created in the 19th century and beginning of the 20th.
The Panama Canal was a crucial part to US trade. The canal opened up and made it easier for trade from Eastern countries, to get to the west coast. While being built, the workers suffered from many diseases spread by mosquitoes like Malaria and Yellow Fever.
The USS Maine was destroyed in the Havana harbor, it was believed that it was destroyed by the Spanish. Rumors went around that it was intentionally destroyed, but found out it was a fire in the ammunition room. Spanish American war was started because of this act.
Hawaii was crucial for US trade in the Pacific. President Grover Cleveland did not want to annex Hawaii, but as soon as his presidency passed, the next president sent troops into Hawaii immediately. Hawaii became the 50th state and boosted trade in the US.