With Supernatural coming to an end after its upcoming 15th season, former cast member Jeffrey Dean Morgan has shared a message to the cast and crew of the long-running CW series.Morgan, who appeared in the first two seasons as the protagonists' father, John Winchester, posted a message on his Twitter account congratulating the cast and crew for the series' record-breaking run, along with expressing well wishes to his former co-stars and the show's loyal fanbase.RELATED: Amell and Padalecki Toast the End of Arrow and Supernatural

Morgan guest-starred for this season's 300th episode, reprising his previous role plucked from a moment of time before the character's untimely demise. Before being returned to his proper place in time, John Winchester expressed his pride in both his sons in an emotional moment after one last family dinner.

Fans around the world were shocked last week to learn that The CW would be ending Supernatural after its next season. With its 15th and final season expected to run for 20 episodes, the series is already the longest running sci-fi/fantasy series in American broadcast television history.

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Airing Thursdays at 8 p.m. ET/PT on The CW, Supernatural stars Jensen Ackles, Jared Padalecki, Misha Collins and Alexander Calvert. The Season 14 finale airs on Thursday, April 25.