It seems like only yesterday that cars had a single side mirror, which screwed onto the drivers side door or fender. There weren't mirrors inside for awhile, and no one had a mirror on the passenger side, except for a few car customizers who were able to jerry-rig a left side mirror to fit on the right. Some even mounted them way out on the front fenders. While that might have looked cool, it wasn't very functional.
For a number of years, we struggled with those cheap factory side mirrors, which broke easily and couldn't be replaced. Most weren't made of enough metal to even be welded. When they did work, we rolled down the window and adjusted them by hand. This was a tricky manuever because you had to reach outward to get at them, which sadly wasn't your normal driving position. So, you played around awhile, leaning out, adjusting, leaning back in, swearing, leaning back out again, and so on!
What a treat it was when they made them remote from the inside, and then, when they figured out how to make that electric. Getting that second mirror on the right was next, although many of those remained manual, even after the driver one went electric. I think it had to do with running the wiring that distance. Of course, after most cars had that right side mirror, they magnified it, and then they had to emblazen that warning on it about things appearing closer than reality.
Some of the early minivans had custom built-in side mirrors which were part of the door panel. A slick trick until your wife backed out of the garage a little too eagerly and took one off. It wasn't as easy as replacing a mirror, it involved a lot of bondo and body work!
Today, replacement car mirrors are available through many after-market webstores. You can get them ordered through your local auto parts store, but you'll wait longer and pay more. Even the electric ones, which seem scary at first, are pretty simple to replace. Good thing, cuz my wife still seems to attack the garage door framing with them!! Or the drive-thru at the bank!!!