This paper concerns the development of the augmentation system of the English absolute construction (AC). The AC is a schematic non-finite construction consisting of a (pro-) nominal head and a predicate and typically expressing adverbial meaning; the construction may be introduced by a preposition. It is argued on the basis of extensive corpus data that one of these introductory prepositions or augmentors, with, has grammaticalized from a preposition-like item indicating the specific relation of manner/accompanying circumstance to a semantically bleached “absolute marker.” In this context, the study of the with-AC in its entirety is argued to benefit from a grammatical constructionalization perspective (Trousdale 2012; Traugott & Trousdale 2013) in that the construction meets the three defining criteria of this process: increased generalization, increased syntactic productivity, and decreased compositionality. It is then shown how the shifts within the augmentation system affected the dynamics of the AC in its entirety as a set of augmentors indicating specific semantics was replaced by a single augmentor, with, whose presence or absence is related to ease of processing, as confirmed by a regression analysis. Finally, a possible route for further, future constructionalization is briefly touched upon.