The pedagogic value of using archival holdings for the teaching of history has long been appreciated. Using primary sources in the teaching of history transcends the rote learning of facts and figures. It encourages critical thinking skills, introducing students to issues of context, selection and bias, to the nature of collective memory and to other like aspects in the construction of history. As Professor Peter Seixas, Canada Research Chair in the Study of Historical Consciousness, has observed, "historians do have something very important to offer students, which is neither the one big story, nor the recall of a common set of facts, but rather a way of using the traces of the past to construct meaningful stories in the present." Many constraints ranging from the fragility and rarity of documents to the physical and intellectual inaccessibility of the record have, however, hindered the use of primary sources in the classroom. When primary sources are used for teaching, there is a tendency--even amongst those with training in history--to consider them solely as illustrations to lesson plans and classroom activities, not to fully explore their greater contextual and historical value. This article discusses the traditional challenge of teaching history in the classroom and some problems in access and use of primary sources. This article also discusses new possibilities and some challenges in teaching history using on-line primary sources. (Contains 32 notes.)