Answer:
was issuing
Step-by-step explanation:
The past progressive tense is used to indicate continuity of action in a specific point in the past and is formed with the verb "to be" in the past tense (was or were) plus the present participle of the verb, (Created with the base form of the verb + -ing).
"Was" is the conjugation of the verb "to be" of "the colony of Massachusetts" as this subject is in the third person singular.
And "issuing" is the present participle of the verb: it is made of the base form of the verb "issue" + "ing".