You can find my thoughts/findings on the representation of American cultures here. It's always great to find that what you and everyone you know has dedicated their life to studying receives a single awful paragraph in just one, upper level textbook. Americans are clueless about the most basic facts on the very places they live, and not through any fault of their own.

I hate textbooks, and I don't use them in my own classes.

They are written by committee, often, as /u/CommodoreCoCo says, they turn complex subjects into a paragraph, and they GET SHIT FUCKING WRONG! I don't mean errors of nuance, I mean passing off complete fiction as facts. Stuff like saying all Roman citizens participated in the Plebeian Assembly. I have TAed world history courses and I can pick out bullshit in textbooks on Mesoamerican history, which I know next to nothing about!

And then there is the notion that because a course requires such and such a book the book has some inherent authority.

Burn them all.

I much prefer that my students work from primary sources and scholarship, not textbooks.

Here's a data point for you. Out of curiosity, a couple of years ago I bought a used copy of US History for Christian Schools, published by Bob Jones University, 2nd ed. (current edition is 3rd, I think). I was surprised to discover that it was pretty good. I mean, it doesn't have the depth I would prefer, but as a middle/high school textbook, it wasn't bad. It is, like many college history textbooks, a summary of the mainstream scholarship, and clearly derived from other, similar textbooks. The topics covered, periodization, etc. were all very conventional. The difference between it and a "regular" textbook was, as far as I could tell, additional sections on the history of religion.

As a high school teacher, I have very mixed feelings about textbooks. On the one hand, they are often terrible for all the reasons that other users have mentioned. Textbooks too often shape the very foundation of the course. Unfortunately, students usually accept information from the textbook without questioning it. Sometimes, textbooks include clear biases to make them more appealing for certain political narratives. In my experience, textbooks are often too hard to read for young students, students with special needs, and students learning English as a second language (which almost immediately makes them “hate” history). If I’m going to use the textbook, I have to spend class time teaching how to read a textbook. More troubling, textbooks rarely include anything about historical thinking, primary source analysis, analytical writing, or research. I always include these skills in my classes, but I have to find all that material myself. Finally, research has pretty consistently shown that students learn more when they are actively making meaning of the material. Passively reading the textbook, listening to lectures, and taking multiple choice tests are about the worst ways to help students learn, and yet this style of instruction is incredibly common at both the secondary and collegiate level.

On the other hand, textbooks are handy because they are generally designed to meet the state standards, so if a teacher follows the book, he or she is also meeting the law. This is especially important today in many states where tests and teacher performance are the be-all-and-end-all of the classroom experience. Teachers teach the textbook to teach the test. Often, textbooks come with lots of other resources that save teachers time, which they can then use to go to meetings, work with parents, lead a club, coach a team, clean their desk, differentiate instruction, grade stuff, spend time with their own families, or catch up on Game of Thrones.

Frequently, “history” teachers are actually trained as social studies teachers, which means a “history” teacher might have a strong background in a subject area other than history. The textbook, then, allows these teachers to do a reasonably decent job helping students learn the basic information with minimal preparation or financial burden. Now imagine you are a teacher with three or four or five or six classes that you have to plan for EVERY NIGHT on subjects for which you are only marginally prepared. Failure is not an option when working with teenagers; you have to have a lesson planned otherwise the students with destroy you. Relying on the textbook is a way to save yourself a little bit of time. I’m not condoning that type of teaching or teacher preparation, but it’s the reality. Therefore in my opinion, textbooks are a mixed bag that are a symptom of a larger problem of overworked and under-prepared teachers.

As much as we like to criticize textbooks, does it really even matter? Are textbooks, even the terrible ones, good enough? I’ve been wrestling with this question throughout my career. People who frequent this subreddit, I’m willing to guess, are/were intrinsically motivated students, fairly high achievers, and individuals who come to history class with a fair amount of background knowledge. For these learners, the criticisms leveled here against textbooks are totally valid because sometimes relying on the textbook is lazy teaching that can harm these students. But consider for a moment the other 75% of students I see in my classes: the students who know virtually nothing about history, who don’t like history and have already decided that they never will, who have never had a good experience with history or school in general, who have little to no desire to go to college or take an advanced-level class, who are going to do some but not all of the classwork (and even if they don’t do all the work, they will still pass the class with a C- or a D+ so what difference does it make?), who don’t study or take notes, who are keeping an eye on the clock because lunch is in 34 minutes, who just felt their phone buzz in their pocket from the student they secretly have a crush on, who forgot their sweatshirt today and are sitting under the vent that blows out cold air unable to concentrate, who play sports after school which represents the only activity that they really get excited about, who after practice go to work at Taco John’s for three hours then come home to spend a few fleeting hours on the couch snapchatting and playing xbox in a small, single family duplex before going to bed and doing it all again tomorrow. I love working with these students, but my goodess, it is hard to get them to learn history. Graduate students, textbook writers, and college professors will never work with these students, but they are telling me I should teach these kids about the Safavid Dynasty? These kids are great people, so nice, so funny, so hormonal, so impulsive, so lazy, but realistically, will they ever need to know about the Kievan Rus? Does it really make much of a difference if the textbook calls the Middle Ages the “Dark” Ages? Even my best lessons filled with critical thinking and historical controversy are met with apathy at best. I try my best to avoid the problems with the textbook, but there is so much more going on in a classroom that teachers have to deal with.

In case you’re wondering, here’s how I teach my courses using (but not relying on) the textbook: I start a unit that I organize myself independently of what the book suggests. I have students read out of the textbook the relevant sections to get enough background information to understand the jist of what was going on. Then, for most of the rest of the unit, I use primary source investigations, videos and documentaries, supplementary articles that I hunt down, discussions, simulations, hands-on type research activities, creative writing, and collaborative structured controversies. Towards the end of the unit, I do several review lectures during which I summarize what students SHOULD have been learning from the textbook and the other lessons. All told, I spend two to three hours a night planning lessons and five to eight hours on weekends grading and preparing for the upcoming week. For assessments, I have students write essays or do projects instead of taking tests because I think the skills they develop doing these are more valuable for them in the long run.

TL;DR I think textbooks are a mixed bag that are a symptom of a larger problem.