This article examines developments in electromagnetism and field physics during the early nineteenth century, when electricity had become a fully respected area of research. It begins with a discussion of the ‘Volta’s pile’, an apparatus developed by Alessandro Volta, along with mathematical approaches to electricity and Hans-Christian Ørsted’s discovery of electromagnetism. It then reviews the work of André-Marie Ampère and the Biot–Savart law, introduced by Jean Baptiste Biot and Félix Savart; developments in electrodynamics during the period 1821–1826; and Michael Faraday’s research initiative in electromagnetism, and especially electromagnetic induction and the electrotonic state. It also looks at three important developments in electromagnetism during the 1820s: galvanometers, electromagnets, and Arago’s effect. Finally, it describes Lenz’s law, electromagnetic generators, the electromagnetic telegraph, the Faraday effect, diamagnetism, and the question of polarity as well as the role of mathematics in Faraday’s theories.