Answer:
The best way to combine sentences 1 and 2 is "In 1751, the Philadelphia Provincial Assembly had a bell made for the new State House"
Step-by-step explanation:
In roder to combine both sentences, the subject "it" is deleted since the personal pronoun makes reference to the noun "bell". Also, the verb to be "was" is deleted since both sentences are linked and the main verb is in sentence 1.
Sentence 2 "It was for the new State House" can be easily combined since it is short and its subject is a personal pronoun that is previously mentioned in sentence 1.