The past perfect progressive is a verb tense that indicates an action that began in the past, continued in the past, and ended at a defined point in the past. It has the following construction:
The modal verb "had" + "been" +the present participle of a verb (which it's the root verb + ing).
So, the past perfect progressive of the verb "hope" is "had been hoping." The full sentence would be "The British government had been hoping to make the colonists trade exclusively with England."
