James Clerk Maxwell was a Scottish physicist and mathematician born on June 13, 1831, and is best known for formulating the classical theory of electromagnetic radiation, bringing together electricity, magnetism, and light as manifestations of the same phenomenon. His most famous contribution, Maxwell's equations, laid the foundation for modern physics and significantly influenced fields such as optics, electrical engineering, and cosmology. Maxwell passed away on November 5, 1879, leaving a lasting legacy in the scientific community.