As you probably know, there are three branches that form the U.S federal government: the Executive branch, the Judicial branch, and the Legislative branch also known as Congress. Congress is made up of two branches: the Senate, and the House of Representatives. There are a total of 100 senators in the Senate (two for each state), where each senator has a term of six years. On the other hand, there are 435 members that make up the House of Representatives, where each state has a certain number of representatives depending on the size of its population. In addition, each representative has a term of two years. Together, the main role of Congress is to make laws. However, there are other roles that Congress also has and thus is why it is important to vote for your state senators and representatives, just as much as is it to vote for the U.S president. Other roles of Congress include: declaring war, impeaching and trying public and federal officers if accused of a crime, approving or denying presidential appointments--as well as treaties, and the power to coin money, collect taxes from the public and decide how to spend it for the national government.
