Nikola Tesla made significant contributions toward the development of alternating current (AC) electricity. His invention of the AC induction motor and transformer allowed for the efficient transmission of electricity over long distances. Tesla's work not only revolutionized how electricity was generated and distributed but also laid the groundwork for modern electrical power systems. His vision of a world powered by AC electricity helped shape the future of electrical engineering and made electricity accessible to millions, highlighting his role as a pioneer in the field.