A concise chronological account explains how electromagnetic induction experiments gave rise to modern alternating-current transformers, moving from early induction coils to refined core-and-winding designs. The narrative connects fundamental principles—magnetic circuits, coupling, and induced electromotive force—with practical engineering aims such as reducing resistance, optimizing coil proportions and symmetry, and improving coefficient of induction. It surveys successive inventions and patent disputes, contrasts polar and non-polar arrangements, and describes how iterative refinements in core materials, winding techniques, and circuit form enabled reliable voltage transformation for lighting and power distribution.