Jack Welch joined GE in 1960 as a chemical engineer and steadily rose through the ranks to become CEO in 1981. During his tenure, he transformed GE from a $12 billion conglomerate into the world's largest company valued at $410 billion. Welch emphasized creating a culture of accountability, rewarding risk-taking, and rapidly removing underperforming business units and employees. After retiring from GE in 2001, he authored several books on management and taught at MIT. Widely regarded as one of the most successful business leaders of the 20th century, Welch is credited with revolutionizing GE and changing how American companies are managed.