Your introduction needs to take the form of something like this. It provides a context for the document, identifies the circumstances in which the speech was given and recognises that ambiguity and exaggeration was (and still is) a central feature of political oratory.
The problem with what you’ve written is that, although you address the issue of the three explanations for Chartism’s support you do so in a general way and do not focus sufficiently on the source. I would be inclined to divide your piece into five sections: introduction, economic, national political movement and inclusive cultural community and conclusion in which you address the issue of which, if any, is stressed most strongly by the speaker. What you’ve written is a commentary using secondary sources to sustain your argument. You need to be very clear what your argument is and how the source reinforces that argument.
The introduction I’ve written is all you need to start. Omit any discussion of Cartwright, his significance was to the period between 1815 and