Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the Reciprocity Treaty of 1875. Much of the harbor and surrounding lands are now a United States Navy deep-water naval base. It is also the headquarters of the United States Pacific Fleet. The U.S. government first obtained exclusive use of the inlet and the right to maintain a repair and coaling station for ships here in 1887. The surprise attack by the Imperial Japanese Navy on December 7, 1941, led the United States to declare war on the Empire of Japan, making the attack on Pearl Harbor the immediate cause of the United States' entry into World War II.

The United States Senate is the upper chamber of the United States Congress, with the House of Representatives being the lower chamber. Together they compose the national bicameral legislature of the United States.

The composition and powers of the Senate are established by Article One of the United States Constitution. The Senate is composed of senators, each of whom represents a single state in its entirety. Each state is equally represented by two senators who serve staggered terms of six years. There are currently 100 senators representing the 50 states. The vice president of the United States serves as presiding officer and president of the Senate by virtue of that office, and has a vote only if the senators are equally divided. In the vice president's absence, the president pro tempore, who is traditionally the senior member of the party holding a majority of seats, presides over the Senate.

As the upper chamber of Congress, the Senate has several powers of advice and consent which are unique to it. These include the approval of treaties, and the confirmation of Cabinet secretaries, federal judges (including Federal Supreme Court justices), flag officers, regulatory officials, ambassadors, other federal executive officials and federal uniformed officers. If no candidate receives a majority of electors for vice president, the duty falls to the Senate to elect one of the top two recipients of electors for that office. The Senate conducts trials of those impeached by the House.

The Senate is widely considered both a more deliberative and more prestigious body than the House of Representatives due to its longer terms, smaller size, and statewide constituencies, which historically led to a more collegial and less partisan atmosphere.From 1789 to 1913, senators were appointed by legislatures of the states they represented. They are now elected by popular vote following the ratification of the Seventeenth Amendment in 1913. In the early 1920s, the practice of majority and minority parties electing their floor leaders began. The Senate's legislative and executive business is managed and scheduled by the Senate majority leader.

The Senate chamber is located in the north wing of the Capitol Building in Washington, D.C.