As according to the separation of powers, each of the three branches is to have a different job. The executive branch executes the law, the judicial branch interprets the law, and the legislative branch makes the laws. Because congress is part of the executive branch, their job would be to execute or introduce the law.
The outcome of the Spanish-American War (resulting in a US victory) made it so that the people of Cuba & Puerto Rico came under the US rule as procterates. This meant that while they aren't "colonies", they were under the US government & had to obey US rules.
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This would be describing a "thesis", which basically means an argument made by a historian based on original research (primary sources) and secondary research to add to an existing body of knowledge.
D
Democrats favor more Federal government control while Republicans prefer less control.