ROTARY PHONES

[Carsman]

Three way calling. When my husband went to Guantanamo Bay he would call me up on the phone and I would do three way calling as a favor so his roommate could talk to his wife.

Three way calling is the more modern day feature.You actually had to "dial" the wife, it was not connected to your line until you did.

"Party Lines" was sharing the "same phone number" (line) with complete strangers. You could be talking on the phone and they could pick up their phone (their line was connected to yours) and interrupt you, or worse "listen" in on you conversation.