When I was a very small child, home-schooling was a rare thing in the United States. By the time I was approaching kindergarten age, it wasn't a completely new idea, but it was still uncommon and widely considered weird.
Reasons for choosing this path are many.
- Little trust in government schools to adequately educate
- Religious objections to the state curriculum
- Kids with special needs poorly served by the school district
- Advanced students who needed more opportunities than school allowed
- Some just wanted to try a different model of learning.
Often a combination of these factors applied to any given family's choice.
My mother had a teaching degree, so this smoothed some ruffled feathers among critics because she had official qualifications to teach. However, I would like to encourage any parent willing to put forth the effort whether they are accredited or not. After all, if the government schools didn't even equip you with the knowledge to help teach an elementary student, do you really want to send your kids there?
I am told I was trying to teach myself to read at a very early age, and I remember my mother reading aloud and taking me to the local library. Recent studies have confirmed that reading to children promotes early literacy. I remember many books in the house, and also wanting to know what that yellow-haired kid and the tiger were doing in the Sunday Funnies. I don't know where she got the materials, but my mother used The Writing Road to Reading to teach penmanship, phonics, and eventually even cursive, although that would be a few years ahead.
Everything was very experimental at the time, with few companies supporting homeschoolers. My parents were quite religious, and I can only remember two publishers actively supporting home-schooling for Christians: Bob Jones University Press and Abeka (Pensacola Christian College). I know both are considered problematic to today's critics. Bob Jones himself was an avowed segregationist way back when, but his university apparently did strive to set academic standards which earned respect. Pensacola Christian College is extremely socially conservative. Both explicitly promote theology in their materials. All of this rubs secular folks the wrong way. However, the core academic material was solid.

I still have my high school copy of the English Handbook for Christian Schools published by Bob Jones University Press on my reference shelf. It's still a useful book.
My mother initially elected to start with the BJU Press curriculum for most subjects. There were book lessons, hands-on activities, and more. As I progressed through the grades, curriculum choices were dictated by budget, reviews from other parents, and availability of second-hand books from other families with older kids. We eventually incorporated material from Abeka and other publishers. We used Saxon Math as well once I approached the middle grades.
Critics of homeschooling like to portray homeschoolers as a bunch of insular religious nutcases with no social interaction. This is odd, considering how the government option involves age segregation, praying to the government flag, and regimented schedules. Even then before the internet, parents found ways to network, plan museum field trips, hold all-ages athletic events, take turns teaching specialized courses, and in general promote social interaction with lots of enriching activities. It also takes a lot less time overall to adequately cover a day's learning, so there was time to focus on individual interests, and even participate in real-life experiences. I know there was an effort to integrate subjects and show how they all interconnect.
There is also flexibility to spend more time on a challenging subject, or permission to speed ahead when things take less time. School bells and class times are really an artificial way to learn based on a factory idea of stamping knowledge on an assembly line, and it does not really work well. Modern education seems designed to waste the time and attention of students who learn faster, and punish those who need any more time than that allotted. Additionally, homework is often assigned requiring de facto homeschooling on top of the time in class despite many arguments it adds no benefits. As a librarian, I even saw reading exercises assigned to kids with dyslexia or other challenges leading to a counterproductive bitter attitude toward reading.
Back to my recollections, though.
Early on, as I learned basic reading and mathematics, I was introduced to my mother's coupon clipping and shopping plans. Other kids got to tag along and see what their parents did for work, help out with charitable activities, and get their hands dirty with what the trendy folks today call "homesteading." We always had a garden, and I helped plant and harvest vegetables. I also eventually learned some basics helping my mother at a natural foods co-op, including rotating goods when stocking shelves. Scouting, 4H, and church activities also gave learning opportunities to many.
Even today, home-schooling is a fringe movement, but it has been growing over the decades. Back then, it was subversive. I know we took standardized tests regularly just to make sure we had proof I was in fact learning just in case the government decided we needed to be put under a microscope. I was consistently in the 90th percentile or better, for the record. Now it's approaching mainstream, and while lots of people still think it's odd (or even dangerous), it's not nearly as foreign as it was during the days of the George H.W. Bush administration!
As my siblings got older and started their own education at home, I became more and more responsible for my own learning. It wasn't totally unsupervised, but I started choosing which courses and publishers I wanted, and scheduled my studies to pace myself through the academic calendar year. I think my experience prepared me for self-directed learning long before college, so I already had the mindset for choosing classes. I also believe the material I had gave me a better education than I would have received at a public school. We elder millennial home school students were an experiment in many ways, and our parents were pioneers, but I think it was a success overall.
I know this is a vague overview, but if there's interest, I can also share some more specific thoughts about pros and cons from my perspective, tell about my brief incarcerations in public school, and maybe eventually even tell a few college stories, although those last ones are fairly boring because I wasn't a party animal or athlete. Chime in with a comment if you have questions I should cover in more depth later!

The fact that the usual suspects in the media arm of the OIC (Omni-Industrial Complex) are churning out stink-pieces about homeschooling with increasing frequency should tell you everything you need to know about the trend. But enough about that.
I was actually introduced to Abeka when I was attending a private Christian school before my brief stint in public school immediately prior to homeschooling. I never had any experience with Bob Jones, but up until today, I never heard anything good about it. By the time I started "high school," I was taking correspondence courses through the University of Missouri, which was pretty fun. Some time after getting my engineering degree, I had started to hear rumours that Abeka was declining in quality along with pretty much everything else, so perhaps you might be interested in comparing your old school books to their newer editions, assuming you still have them. I gave most of mine away, with the obvious exception of my Russian books, though I wouldn't be surprised if my sister asks for those soon. Her oldest turns 5 this year, and she turns 40, which I am extremely tempted to tease her about.
My parents ran a secondhand bookshop and I learned to read through sorting and shelving the books according to genre. It's far easier to learn something by applying it in practice than it is by studying it in the abstract in a classroom setting.
I would also argue that a more freeform unschooling learning process is better than dividing knowledge into narrow distinct subjects. My favorite podcasts blend subjects and explain how they interweave. The History of Philosophy Without Any Gaps blends historical chronology and examination of cultural exchange as an essential part of how philosophy grew and developed alongside science and theology. The History of English explores how events in English history changed the language.
I went to public school until 6th grade, then a private school, then a teacher came to our home to teach us. Then I had one year back in public school, I saw it all.
Even though home-schooling was considered WEIRD in the '80s and '90s, nearly all of the home-schooled children of those days received an excellent education. I think many parents were determined to do a better job than the public school would have done, and even felt a certain amount of social pressure to do so. A frequently-heard question from doubters was, "But what about socialization?" As a home-schooling parent, I got so tired of that question, I made a list of all the positive social behaviors I wanted my children to learn, and concluded none of them would be learned in a public school setting. I have been acquainted with dozens (possibly hundreds) of home schooling families over the past 40 years, and can only think of two who did a really poor job of it. And those few children overcame their initial disadvantages with time. That is still a better success rate than the public school system can claim.