This chapter examines how the language resources used to incorporate written historical evidence contribute to the negotiation of values regarding Mapuche people in primary and secondary Chilean official history textbooks. The study considers as a starting point the broad categories proposed by the ENGAGEMENT subsystem of the APPRAISAL system (Martin & White, 2005). Then it explores in detail the metaphorical, more or less evident and non-metaphorical interpersonal and experiential realisations involved in ENGAGEMENT in Spanish, adopting an interstratal tension perspective on the relation between discourse semantics and lexicogrammar strata. The study shows that the monoglossic orientation as well as the heteroglossic orientation of dialogic contraction tend to be realised by history textbook authors through non-metaphorical realisations. However, the inclusion of external voices as [expand: attribute] tends to be done by both metaphorical and non-metaphorical experiential realisations, and also by lexicogrammatical structures that although they cannot be considered as interpersonal or experiential grammatical metaphors, make the external voices less ‘recoverable’.