What year did phone party lines end?

1991 Many of these party lines were around until the 1970s when they started to disappear. I have learned that the last party line was phased out in 1991. In some cases, you did not avoid the exposure to a party line just because you had a private line.

When was the last party line used?

Party lines carried on well into the 70s, but the technology was deemed “a victim of progress” but the last party line was not phased out until 1991 in Woodbury, Connecticut. And, Illinois State University terminated its last party line in 1990.