Yep. Visiting (either going to someone else's house or them coming to ours) was the main form of socializing where I was raised, especially in the winter when the evenings were long and there was less work to do around the farms.
We did this too...every Friday and Saturday night, the parents would get together at one family's home or another. The kids would play together, the parents would chat or play cards, snacks would be served, and oftentimes things rolled into the early morning hours with the kids passed out on the couches. I greatly miss those days. Our family/friend dynamic is no longer set up like that anymore.
That was the general family socializing we did, however if you are talking any kind of get together including sleepovers...
I grew up on a farm outside of a small city that was surrounded by farms for miles in every direction. Farm kids who lived within a half hour radius of the city were all bussed to school in the city--a special school just for the farm kids, since they didn't have a specific city area school to attend. Anyway, that could pose some interesting problems when your best friend lived half an hour drive on one side of the city and you lived half an hour the other direction. It was SUPER COMMON for kids to arrange sleepovers, where you would pack your weekender bag Friday morning, take your bus to school, but then after school, hop on your friend's school bus and go to their place for the ENTIRE WEEKEND. On Monday morning, you would get on their bus (their parent would make your packed lunch), go to school, then take your bus home again Monday evening. Lots of times, parents wouldn't even know the people that their kids were going to stay with, and we were doing this from mid-elementary school onward. Sometimes the whole thing was arranged with a note back and forth between parents in our lunch boxes, sometimes with a quick phone call, because back in those days, being more than 20 minutes from somewhere was long distance calling charges. Occasionally, I would come home and ask if I could go to a friend's place and it might be someone that my parents didn't know personally, but my dad might say, "Is that the Smiths that have the dairy farm south of town?" Oftentimes, my parents wouldn't even know what farm I was staying at, just a general nearby town location like "The Smiths from Farmville" or vice versa for kids that I brought home to our house.
Looking back now, it seems INSANE to me that we did this, but I guess it was a different era. I mean, we had phonebooks so you could look the family up and try to call them if something came up, but superficial details like phone numbers or land location numbers or whatever weren't really part of the equation.
As a sort of an off-shoot to this, one time I had a friend staying over at my place for the weekend. It was a person we knew well and she had been to our home multiple times, but this one time, she got homesick. My mom tried to phone her family (era of only landlines) to arrange to take her home. My mom called and called and called, but nobody ever answered until late Sunday. It turns out that the whole family decided to go on a trip to visit family, left their daughter at our place, did not notify my mom that they were going anywhere, and didn't leave a phone number they could be reached at!!! Normally, my mom would just roll with all of this stuff, but she was NOT HAPPY and was like, "What if something bad had happened???" This was unique in that most farmers don't leave home, so you always know how to track them down. This person's parents both had non-farm jobs.