For years, librarians have shown sample searches that look at bias. They will show something like a MLK site and look at how this figure has hate sites and adulation sites and commercial sites hoping to cash in. When we try to teach MLK, we might just settle for a version that’s heavily edited and talks about him and never get his words into the piece. Or we might fear controversy and just go superficial with certain topics. In elementary schools, this often occurs. The chilling effect is a real thing and it basically works to keep people from teaching in as many ways as they might.
As a U.S. history minor in college, what I learned has had to be updated constantly. The history books that one can read now are more accessible, interesting, and challenging because they rework the notion that American history is (as author James Loewen puts it) a series of inevitable successes. There are some extreme versions of this that get brought out in the media as picking out an alternate reality, however, and as with anything, we have to be careful of understanding the extent to which things are valid. That only comes with wide reading. There aren’t short cuts to the process.
So it’s a bit of “Welcome to being a lifelong learner.” It’s just incredibly tough for busy teachers to do this. The practical tip I’d offer here? Avoid simple solutions or prepackaged approaches to which you add nothing. If you’re teaching a unit–especially if it came from a state commission or a big publisher–modify and undercut it where it needs modifying and subverting. We have done this several times with our text, which does sanitize some history.