1. A system for classifying documents via propagation, comprising: a text identification module to identify within at least one document, text that is highlighted by a user, wherein the document is associated with a classification code based on subject matter of the highlighted text for that document in relation to a predetermined legal issue; a comparison module to compare at least a portion of the highlighted text with one or more unclassified documents; a same document identification module to identify those unclassified documents with text that is the same as the compared portion of the highlighted text in the document; a classification assignment module to automatically assign the classification code of the document to the identified unclassified documents with text that is the same as the compared portion of the highlighted text in the document; a similar identification module to identify those unclassified documents with text that is similar to the compared portion of the highlighted text in the document; a distribution module to provide the unclassified documents with similar text to the user for review and classification; and a processor to execute the modules.