This thesis explores how Anna Letitia Barbauld’s book Lessons for Children Aged Two to Three Years (1778) facilitated the development of the conversational primer. This genre, which has not yet been theorised, may be identified by the way the texts present themselves as verisimilar and replicable sets of conversations, and depict parent-teachers and child-pupils as companions. This genre challenges the idea that there is a dichotomy between ‘adult’ and ‘child’ readers, a concept that inflects many contemporary approaches to children’s literature studies. Through a close reading of Lessons for Children and subsequent conversational primers, this thesis suggests that Barbauld’s Rational Dissenting value of discursive diversity influenced British middle-class children’s culture, enabling the voices of verisimilar children to proliferate children’s books on a previously unknown scale. The Introduction establishes ways in which concepts of child-parent relationships were used as paradigms for understanding modes of government in eighteenth-century Britain. Chapter One examines how children’s books prior to Lessons for Children addressed different types of implied child readers with the aim of producing members of an ideal society. Chapter Two explores how Barbauld created a space in which parents could participate in the children’s literature market through her introduction of the parent-author as a literary trope, her portrayals of verisimilar mother-child interactions in accessible, domestic spaces. Chapter Three charts how Lessons for Children became the prototype from which subsequent conversational primers drew their literary identity. The fourth chapter contextualises Lessons for Children as an expression of Barbauld’s Rational Dissent, and posits that the rise of the conversational primer is indicative of the influence of Rational Dissenting values upon British middle-class children’s culture. Chapter Five contrasts the afterlife of the conversational primer with children’s books that generated readers’ imaginative identification with characters. This comparison suggests that conversational primers encapsulated middle-class Georgian ideals regarding familial learning; an historical specificity that is, in part, responsible for the genre’s popular demise. This thesis studies the lifecycle of the conversational primer in the British children’s literature market. It examines the porousness between paratextual materials and texts, and shows how an individual author stimulated generic development by popularising specific literary tropes. By theorising the genre of the conversational primer, this study provides a new and productive discourse concerning adult-child interactions in children’s literature.