The beginning of *The Wonder Years* is set in 1968.
The series opens with Kevin Arnold preparing to enter junior high in suburban America. Its nostalgic coming-of-age story follows Kevin, Winnie Cooper, and Paul Pfeiffer as they grow up during the late 1960s and early 1970s. The pilot specifically connects the story to 1968, when Winnie's older brother Brian is killed in Vietnam.
The show's timeline is unusually structured: each season generally takes place about 20 years before the season's original broadcast. The program premiered in 1988, so its opening year was 1968; the story then progresses through the early 1970s as Kevin ages from 12 to 17. This setting also places the characters against major events and cultural changes of the era, including the Vietnam War and the changing social climate of the United States.
A common mix-up is confusing the show's production year with its story year. Although the series first aired in 1988, its fictional beginning is two decades earlier.