This monograph is a study of American (U.S.) stage representations of dementia mounted between 1913 and 2019.  Its imbricated strands are playtexts; audiences as both the targets of the productions (artifacts in the marketplace) and as anticipated determinants of legibility; and medical science, both as has been (and is) known to researchers and, more importantly, as it has been (and is) known to educated general audiences. As the Baby Boom generation finds itself solidly in the category of “Senior,” interest in plays that address personal and social issues around cognitive decline as a potentially frightening and expensive experience, no two iterations of which are identical, have, understandably, burgeoned. This study shines a spotlight on eleven dementia plays that have been produced in the United States over the past century, and seeks, in the words of medical humanities scholar Anne Whitehead, to “open up, and to hold open, central ethical questions of responsiveness, interpretation, responsibility, complicity and care.”