They did away with party lines in my area when I was still in grade school. I should have guessed when you said two longs and a short ring. They may have used that out in the middle of nowhere on some old step by step office. But that is why the government let AT&T become a monopoly, they had to provide Universal Service. Every little town and village could have phone service even if they had to lose money to provide that service. The break up of the Bell System was started by companies that were "Cream Skimmers" they only wanted to take the heavy populated areas and not give service to the none profitable locations. The sad part was the government let them get away with it.
and still does. Which is why Verizon wants everyone on FIOS. Its a feature and unregulated. Once they have enough people off of copper they can make a rate case to do away with provider of last resort.
I worked in NJ in the late 80's and there were still party lines on digital switches. It wasnt a point of wanting to get rid of it, it was mandated to have if you had enough people with party lines. So if you have a person south, west, north, and east the last people on their party lines, there are 4 seperate party lines and people alone on a line and paying party line service. We tied them all together so that they were on a party line again, most paid for a private line, at that point the company was able to get a rate case to get rid of party lines.