Jack Welch led General Electric Co. through two decades of unparalleled growth and transformation, with a brash style that single-handedly remade the conglomerate and changed the landscape of U.S. corporations. He died Sunday at age 84.

Mr. Welch’s success, driven by a hard-nosed strategy to slash less profitable businesses and unproductive employees, made him an international celebrity in the 1980s and drove GE to become the most valuable U.S. company during the 1990s. He groomed a generation of business leaders who went...