How did the telephone work the first time?

1. you picked up the earpiece from the hook and listened to verify nobody else was using your party line
2. you turned the magneto crank to signal the operator that you wanted to make a call
3. when the operator asked "number please?" you gave the number you wanted to call (usually an urban phone number was 3 or 4 digits followed by a letter, the digits gave the phone line and the letter the party on that line - rural phone numbers were more complex)
4. the operator connected you.

If someone was calling you, you learned to recognize your "ring pattern" and only answer the phone if the call was for you, not someone else on the party line.

Urban party lines could have 2 to 10 parties sharing a single line. Rural party lines sometimes had even more.

Usually only businesses and professionals (e.g. doctors and lawyers) could afford the extra charges for having a dedicated single party line.