- The Greatest Generation, also known as the G.I. Generation and the World War II Generation, is the demographic cohort following the Lost Generation and preceding the Silent Generation. The social generation is generally defined as people born from 1901 to 1927. They were shaped by the Great Depression and were the primary generation composing the enlisted forces in World War II. Most people of the Greatest Generation are the parents of the Silent Generation and Baby Boomers, and, in turn, are the children of the Lost Generation.