How did people find old friends and acquaintances before social media?

Way back, and until quite recently, it was quite common for people to write to local newspapers in the UK, for their “Letters to the Editor” page, asking if anyone knew of the X family that used to live in such and such a street, or used to work at Y factory or attend Z school, and would they get in touch.

Before the internet, social media was called “print”.
As others mentioned, there were phone books. People thought nothing of having their name and address listed in a giant paper book, updated and re-issued every year.
There were also city directories, for larger city areas - companies would do the same thing as the phone book, but with sort-by-name, sort-by-address sections.
Most city libraries had several years of these directories. (I found where an old girlfriend and her husband lived this way, even though it was 50 miles out of town.)
For more prominent people, there was “Who’s Who” directories - for example, there was a WW of science professionals in Canada - any university professor or corporate researcher was listed (unless they chose not to respond to the questionnaire) and there was a lot of detail, like age, where degrees came from, current position, marital status, children’s names. etc.
Before the internet, some professional associations published membership lists; plus professionals like doctors, lawyers, etc. obviously had to be publicly visible - at the very least, in the phone book.
You picked up hints and clues from mutual friends, and people who would remember - “oh yeah, they moved out to Denver” or some such; or as someone said, newsletters and alumni updates.
Plus, quite often if it was a marriage more formal than “let’s run down to city hall today!” there was usually an announcement in the newspaper with the names of the happy couple - and maybe a common acquaintance would remember “oh, yea, she married Joe Schloptik 7 years ago!”
It helped if they weren’t named “Smith” or “Jones”; otherwise you could spend hours going through a page or two of fine print for “Jones R”, “Jones Rick”, “Jones Richard” etc.
By the mid-90’s the internet was getting started, and before spam and anonymous harassment became a big thing, I remember a lot of companies and especially universities published email directories online. I sent a few emails to children of my friends along the lines of “wow! you’re in university half-way across the country but I can send you a message because we’re both on the internet.”
If you were really desperate you could hire a detective who knew these and many other tricks, and did not mind calling strangers to ask questions. I think you could look at tax rolls, if they wanted to check the city offices for names.

It’s only with the ubiquity, ease, and permanence of the internet that people have become more reticent about putting personal and localisation details out there.
Before that, you had to really want to find someone.
But of course, long distance calls cost a lot of money, so you had to be motivated to want to look for them.

When facebook took off people would say “You can find old friends.” I don’t want to find them so I never used Facebook. Anyone looking for me on there will be disappointed.

Fundamentally, they didn’t, except in rare cases. When I moved from Montreal to Los Angeles in 1977, I fully expected never to hear of the friends I left behind ever again. Except in a few cases where I deliberately stayed in touch.

So I graduated college in 1995. I imagine it was about a year later when me and my friends started using email in earnest.

Prior to email, the way you kept in touch with old friends was to deliberately keep track of their contact information in a paper address book or Rolodex. Like you had to make a concerted effort to keep track of old friends.

To be honest, there is something kind of liberating never having to hear from people again. Not like I have anything against my old high school or college friends. But to a certain extent, I don’t really find it valuable to have a social network full of middle-aged people I kind of knew as teenagers who I don’t really share anything in common with.
There is also the matter that “networking” back then actually meant something. As opposed to now where people get “referred” by some random acquaintance they met five years ago at a trade show.

You also would ask a mutual friend you were still in touch with if they knew where to find the person. If they didn’t they might know someone who did.
Not as easy as Google.

Sometimes there would be an announcement in the hometown newspaper even if the wedding was out of town so you could see where they moved. Likewise you might see their current location in the obituary of the parent.

I usually wrote to the college or university alumni office and asked if they would address and forward the enclosed stamped letter. Almost always got to the intended recipient.

I was going to say that back then it wouldn’t have worked for me since I never gave them my forwarding address. Then I remembered that I got solicitation mail and phone calls from them fairly quickly after I graduated. This was in 1990. They were able to located me somehow.

Here’s how it worked in prehistoric days.

You’d graduate from high school, everyone promising everyone else they’d stay in touch. Some of them actually did. By the fifth year out of high school, there were enough people who still knew people to put together a reunion committee. The high school would help out with whatever lists they had available, as well as contact information for a student’s parents or younger siblings who still went to that school.

At that point the reunion committee had a pretty good idea how to get in touch with most of the classmates. They’d put a school reunion notice in the local newspaper, and that would bring in a few more names. If someone had heard that Joe Smith had moved to Des Moines, one of the reunion committee would go to a large library with out of town telephone directories and look through the Des Moines directory for any Joe Smith. They’d send postcards to all the Joes and hope one of them was the right one (and was interested in being contacted.

After all that, there would be a reunion, and the list from that reunion would form the core of the list for the next reunion, and so on.

I know that sounds like a lot of work compared to a Google search, but it was surprisingly efficient and effective.

Not high school, but my college published an alumni directory every five years. They would send a letter asking what information (if any) you wanted listed - address, phone number, employee, etc. - and if you wanted to buy a copy. I think I bought one or two before I figured out that I always had up-to-date information on anyone I wanted to keep in touch with.

You find someone who knows a guy who knows a guy who knows a guy…a good-sized city library will also have phone books from all around the country. The phone book method is more helpful when looking for a male, as females have a tendency to change last names, if what you’re looking for is someone you knew when young and single and much time has passed. Though you might find her parents’ number.

I once tracked down a minor league baseball player from the 1950s by looking at articles in his local hometown newspaper about his high school baseball games and looking up his old high school teammates, one of whom was still in touch with him.

It boggles my mind that there was a book that contained the names, addresses and phone numbers of everyone in my city/region, including mine, and it was printed and distributed so that every house in my city/region had a copy.

And we were OK with this.

You could always get an unpublished (not in the phone book) or unlisted (not available to anyone) phone number. And a lot of people did.

And Friendster. A lot of my former classmates were using that back in 2003 and 2004.

You had to pay a fee to be unlisted, though.

PS: “Desperately Seeking Susan

Yes. And you were charged extra for this.

And nobody read your diary unless you gave them specific permission; which you probably didn’t. The things came with locks (easily broken, but you could probably tell if they had been.) They didn’t come with privacy permissions which repeatedly got reset without your permission to let anybody on the planet read them.

Nobody kept track of what you, specifically, were buying at the grocery, or the drugstore. Which did not have surveillance cameras; neither did the streets.

Nobody but you (and anybody you felt like reading them to) knew which news stories you read in the newspaper; or, unless you signed up for Nielsen, which ones you watched on TV.

And most definitely no company that sold books looked over your shoulder as you read, noting which pages and which words you lingered on.

Y’know, it never occurred to me that e-book readers would do that… but now that you mention it, of course they would.

And with no effort at all, you could make an anonymous phone call to any of those people, and they would have no way of finding out who the caller was. Even if they got the police involved, you’d have to call again, and stay on the line long enough for them to trace the call.