Timothy Busfield  Timothy Busfield (born June 12, 1957) is an American actor and director. He has played Elliot Weston on the television series "thirtysomething"; Mark, Kevin Costner's brother-in-law, in "Field of Dreams"; and Danny Concannon on the television series "The West Wing". In 1991 he received a Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series for "thirtysomething". He is also the founder of the 501(c)(3) non-profit children's theatre Fantasy Theatre for Children and B Street Theatre. Busfield was born June 12, 1957, in Lansing, Michigan, the son of drama professor Roger and secretary Jean Busfield. He graduated from East Lansing High School in 1975. He landed his first professional acting job at 18 in a children's theater adaptation of Shakespeare's "A Midsummer Night's Dream". Busfield studied drama at East Tennessee State University and traveled frequently with the Actors Theater of Louisville, which took him to Europe and Israel. In 1981, he moved to New York City, NY, where he joined the Circle Repertory Company for their production of Lanford Wilson's "Talley and Son". That same year, he landed his first film role with a bit part as a mortar-bearing soldier in the comedy classic, "Stripes" (1981). More stage work followed, including a stint as understudy to Matthew Broderick in "Brighton Beach Memoirs" in 1982. The following year, Busfield relocated to Los Angeles to join the cast of "Reggie" (ABC, 1983), a short-lived comedy based on the British television series "The Fall and Rise of Reginald Perrin" (BBC, 1976-79). The year 1984 proved to be a busy one for Busfield; not only did he land his first substantial film role as Arnold Poindexter, the goofiest of the geek fraternity brothers in the hit comedy "Revenge of the Nerds" (1984) and its 1987 sequel, but he joined the cast of the long-running drama "Trapper John, M.D." (CBS, 1979-1986), starring as the son of Pernell Roberts' Trapper John McIntyre. He held the role until the series' conclusion in 1986. Following the demise of "Trapper John", he joined forces with his brother Buck to create the Fantasy Theatre, a professional touring company for children's audiences - and later Honorary State Children's Theater for California - based in his new hometown of Sacramento, CA.