Around episode 20 of the first season, the character of Chester Cooper no longer appears.
He was the butler in the pilot, and then he became Glen's secretary.
The actor's name, Philip Coolidge, is dropped from the opening credits beginning with episode 20.
Does anyone know when his last appearance was, and was there any explanation as to where he went?
I'm missing episodes 17 and 18, so maybe something happened in those episodes.
For example, I never heard anyone say, "Mr. Cooper had to leave town to take care of a sick relative," or "Mr. Cooper got a new job," etc.

I just did a quick Google search for Phillip Coolidge. From April through August of 1964, he appeared in a production of Hamlet on Broadway. I dont see anything else he appeared in after that. The 1964 dates would coincide with his absence on The Farrmer's Daughter. I suppose he just wandered off with the family cook, Millie.
According to FindAGrave, he died from lung cancer in 1967.

Even though I own the 16 dvd set, I would love to see it again on tv. It was my favorite tv show during its first run. I would have enjoyed a fourth season, perhaps with Katy and Glen having a liitle girl to round out the family.

If only I had had the good sense to keep the episodes I taped fromCBN during the 1980's...

Thanks for the info, marypat! Glad to see you found the 16-disc set. Isn't it an improvement over the 9-disc set?
Since I originally posted my inquiry, I have learned a few more things.
The first season had 36 episodes, but the show only filmed 17 episodes initially for the first season and went on hiatus ( The show was filmed months in advance of its Sept. 1963 premiere date). ABC didn't want to commit to a full season for a new show in case it was a bomb. After the show premiered in Sept. 1963, and got decent ratings, ABC ordered another 19 episodes to round out the first season. This is when the show was re-tweaked, and the Mr. Cooper character was dropped. Still have no idea if there was an onscreen explanation, but probably not. The writers probably wanted to go a different direction like focusing on the Glen/Katy romance, or maybe the actor was unavailable. Sort of like when the actress who played Aunt Clara on Bewitched died, her character was never mentioned again.

Ronny:
Thanks for the first season info. It does seem to fit in with the disappearence of Mr. Cooper.
I love the 16 dvd set, but some of the episodes are shorter than the 9 disc set--go figure.
So, for 2 episodes (the 1st episode after the wedding and the episode where Katy reads Glen's late wife's diary) the 16 disc set cuts out a few important scenes. So i watch those episodes on the 9 disc set.

Maybe someday we'll get a real set of dvds. We can only hope.

I have the 9 disc set, unfortunately. Not because most of the episodes look terrible (as if recorded off of a UHF channel from the old days) but the worst is many of the discs DON'T even PLAY on my DVD players and to top it off the so-called menus don't work either, you have to fast forward thru the disc to get to the next episode, this is WHEN you can play the disc at all. It is one of the worst sets of discs I have ever gotten. :(

Ronny:
Thanks for the insight on the first season filming schedule. I think that the first few episodes from season1 showed scenes filmed in DC, and the boys seemed much younger than they did in the later ones (particularly Steve).