History of educational programming languages
I'd suggest you reconsider. To understand e.g. why Pascal is a nice teaching language you need to have a decent background in programming languages, some notion of teaching programming (the misconceptions by learners are often way, way different than you'd guess in your wildest nightmare), and hopefully some experience teaching.
Languages specifically designed for teaching are a wildly varied  bunch, most never won any sort of wider traction. Or if they did, they soon outgrew the &quot;to teach programming&quot; range. Take a peek at BASIC and its recent incarnations (don't look like BASIC at all); languages like Pascal (designed to be easy to implement and teach); Logo and even (to some extent) Scheme are part of the flock.