Over the last 300 years, the into-causative (he talked his father into giving him money) increased in frequency and lexical diversity. Changes of this kind are often taken as evidence of functional expansion. From a Construction Grammar (CxG) perspective, this paper argues that what appears to be a loss of restrictions on the verbal slot results from changes in argument mapping links. As the construction provides the argument roles by mapping semantics (causer, causee, result) onto syntax (subject, object, oblique), stronger mapping links increasingly facilitated the use of verbs that are semantically and syntactically atypical for the expression of causation. Data from the Corpus of Historical American English confirm three predictions of this hypothesis with respect to shifts in (i) the semantic classes of matrix verbs, (ii) their general argument structure preferences, and (iii) voice-marking. The results provide evidence for a subtle semantic change from movement into action to manner of causation. The increase in frequency and productivity are hence explained as the consequence of the syntactic form becoming a more reliable cue for causative meaning. We discuss implications for models of language change against the background of current issues in Diachronic Construction Grammar (DCxG) pertaining to constructionalization vs. constructional change.