I'm not sure if an Earth interacting CME have been observed during a solar eclipse, but below you can see an old drawing from 1860s solar eclipse that shows an interesting structure in the southwest part that resembles a CME. This probably is then the oldest CME ever witnessed!
Ground or space-based coronagraphs have routinely observed CME from 1970s by using coronagraphs that creates an 'artificial eclipse' by placing an occulting disk over the image of the Sun to see the faint corona. Coronagraph records white-light that has scattered from the electrons in the corona.