Final answer:
The Senate is called the upper house because of its powers and the structure of its representation.
Step-by-step explanation:
The Senate is called the upper house because it is considered to be the higher chamber of the United States Congress. It is referred to as the upper house because of its unique powers and responsibilities, which include reviewing and approving legislation, confirming presidential nominations, and ratifying treaties. The structure of the Senate, with two senators from each state, regardless of population, also contributes to its status as the upper house.
Learn more about Structure and powers of the United States Senate