The last issue of TCRecord includes a review of a book that I wasn't aware of before, but that certainly looks interesting: "Tools of American Mathematics Teaching, 1800-2000", by Peggy Aldrich Kidwell, Amy Ackerberg-Hastings, and David Lindsay Roberts. The book was published last year. Here is a taster of Alexander P. Karp's excellent review of the book:
In today’s classrooms graphing calculators have become routine, yet thousands of teachers can easily recall a time when they did not exist. Not so with the blackboard, which seems to us something that is almost as old as the idea of education itself. This, however, is by no means the case. Two hundred years ago, and for several decades afterwards, blackboards were a novelty in American classrooms and their use was regarded as a particular feature of teaching style. And indeed, the transition from small tablets made of slate to a large blackboard for the whole class went along with a transition to working simultaneously with a large group of students—a transition that can hardly be viewed as anything other than fundamental.