Focusing on electromagnetism, this third volume of a four-volume textbook covers the electric field under static conditions, constant electric currents and their laws, the magnetic field in a vacuum, electromagnetic induction, magnetic energy under static conditions, the magnetic properties of matter, and the unified description of electromagnetic phenomena provided by Maxwell's equations. The four-volume textbook as a whole covers electromagnetism, mechanics, fluids and thermodynamics, and waves and light, and is designed to reflect the typical syllabus during the first two years of a calculus-based university physics program. Throughout all four volumes, particular attention is paid to in-depth clarification of conceptual aspects, and to this end, the historical roots of the principal concepts are traced. Emphasis is also consistently placed on the experimental basis of the concepts.