The First Amendment to the United States Constitution guarantees the right of all citizens to communicate with their elected representatives. Congress is comprised of the Senate and the House of Representatives. Although Members of both Houses are technically Congressmen/Congresswomen, in the public minds the word Congressmen identifies Members of the House of Representatives. However, when you refer to individual members use Congressman (Name) and Congresswoman (Name).
You may address both current and former Congressmen as Mr./Ms./Mrs./Dr. (Name) which is the same way the House of Representatives formally address each other. It is very important to make certain you are sending your message to the right person representing you in your district. The best way to do this is go to http://www.whoismyrepresentative.com/ and type in your zipcode. Once you have identified the Representative in the United States Congress for your district we will show you how to address them properly in writing.