There are 535 members of the United States Congress, but not just anyone is qualified to become a senator or a representative. The US Constitution lays out certain requirements for the federal officials. After ascertaining that they meet the qualifications, would-be officials still must win their elections.
The United States Congress is made up of two legislative bodies, the Senate and the House of Representatives. Members of the Senate are called "senators" while members of the house are called "representatives." Article I of the the U.S. Constitution calls for a Congress and assigns all legislative powers within the Constitution to that body. Congress is made up of 100 senators and 435 representatives. Each state holds local elections to decide who their Senator or Representative will be, with a majority vote deciding the winner.
Differences between Representatives and Senators
Each state is allowed to send two senators to the Senate. The Vice President of the United States is the President of Congress, although his only constitutional role within Congress is to break a tie vote. Senators serve for six-year terms. The number of representatives a state is allowed to send to Congress depends upon that state's population. Regardless of population, each state must have at least one Representative. Representatives serve for two-year terms. There are no term limits for either body of Congress.
Representatives must be at least 25 years old, must be U.S. citizens for at least seven years and must--at the time of their election--be a resident of the state they are representing. Senators must be at least 30 years old, must be U.S. citizens for at least nine years and must--at the time of their election--be a resident of the state they are representing.