Reverend Alden, the preacher of Walnut Grove, was played by Dabbs Greer over multiple seasons of the show, appearing in 76 episodes over the full run of the series. He is based on the real Reverend Alden which appeared in the Little House books.
He first appears on the episode A Harvest of Friends, the very first episode of the Little House on the Prairie tv series.
His final appearance is in The Last Farewell, when the residents of Walnut Grove blow up the town (except for the church) to prevent Nathan Lassiter from benefiting from the town’s work over the years.
He is one of the few characters to appear in the first and last episodes.