Final answer:
Sentence 1 should be corrected by adding a comma after the introductory clause to properly separate it from the main clause. The correct answer is option 1.
Step-by-step explanation:
The question pertains to sentence correctness in a historical context about the construction of the first navy and USS Constitution. Specifically, it asks for a potential change in sentence 1 from the passage provided.
The correct form of sentence 1 is (1) In the late 1700s, as a new American nation was creating its first navy, shipbuilders were busily constructing a great vessel.
Therefore, the change that should be made to sentence 1 is the addition of a comma after the phrase 'as a new American nation was creating its first navy' to correctly separate the introductory clause from the main clause of the sentence.