Johnny is right - Halloween was not celebrated or even marked in any way in the 50's or 60's in the area of the UK where I grew up. It is a much more recent hype.
Personally, I hate to see small children encouraged to beg from door to door. It doesn't seem to give the right sort of messages at all.

I can't agree with Johnny about M*A*S*H though - its still my favourite TV programme of all time