How Many Seasons was Dallas produced for Television?

Answer:

13 Seasons

Dallas started showing in April 1978 as a five-part miniseries on the CBS network, and then was broadcast on that network for 13 seasons from 1978 to 1991. In those years Mini-Series were a big event for the Networks but it was unusual for a Mini-Series to become a regular TV Series.

Original main cast
Larry Hagman as John Ross "J.R." Ewing, Jr. (1978-1991 - entire run)
Eldest son of Jock and Miss Ellie.
Patrick Duffy as Bobby James Ewing (1978-1985, 1986-1991)
Youngest son of Jock and Miss Ellie.
Barbara Bel Geddes as Eleanor "Miss Ellie" Southworth Ewing Farlow (1978-1984, 1985-1990)
Jock's wife, whose family owned Southfork Ranch originally.
Jim Davis as John Ross "Jock" Ewing, Sr. (1978-1981)
Founder of Ewing Oil and head of the Ewing family.
Linda Gray as Sue Ellen Shepard Ewing (1978-1989)
J.R.'s long-suffering alcoholic wife.
Victoria Principal as Pamela Jean "Pam" Barnes Ewing (1978-1987)
Bobby's wife, who is forced to act as a buffer between the two feuding families.
Charlene Tilton as Lucy Ewing Cooper (1978-1985, 1988-1990)
Gary & Val's daughter. Saucy granddaughter of Jock and Miss Ellie.
Ken Kercheval as Cliff Barnes (1978-1991 - entire run)
Pam's brother, whose schemes are aimed directly against the Ewings, specifically J.R.
Steve Kanaly as Ray Krebbs (1978-1988)
Ranch foreman; Jock's illegitimate son.

Larry Hagman's mother was the famous Mary Martin who played Peter Pan in 1960 on Television as she played it on Broadway in 1954.