DeWilde shared an onscreen camaraderie with both James Stewart and Audie Murphy in the 1957 western "Night Passage". In 1958 deWilde continued his career, starring in "The Missouri Traveler" sharing lead billing with Lee Marvin in another coming-of-age film, this one set in the early 1900s. He made a mark on screen at age 17 as an adolescent father in the 1959 drama "Blue Denim", co-starring Carol Lynley, with the then-mature theme of abortion, even though the word is never used in the film. He guest-starred on many TV series, including "Alcoa Theatre" and the popular Western, "Wagon Train". In the 1959 "Wagon Train" episode, "The Danny Benedict Story", deWilde starred in the title role as the estranged, musically-inclined son of a stern Army colonel.