How did James maxwell invent electromagnetism and electromagnetic waves?

James Clerk Maxwell didn't "invent" electromagnetism; rather, he formulated the existing principles into a coherent theoretical framework. In the mid-19th century, he developed a set of equations, now known as Maxwell's equations, which describe how electric and magnetic fields interact and propagate. These equations predicted the existence of electromagnetic waves, demonstrating that light is an electromagnetic phenomenon. His work laid the foundation for modern physics, uniting electricity, magnetism, and optics into a single theory.