Question: Who was the director of the 1959 American Western film in which the actor, who played Reverend Robert Alden in "Little House on the Prairie", plays a role?
Sentence (from "Dabbs Greer"): He was also portrayed on other shows as a minister, and one of his most remembered roles was as the Reverend Robert Alden in NBC's "Little House on the Prairie".
Relevant evidence: Yes