The purpose served by the structure of the address by President Lincoln is D. to prepare legislators for the difficult decisions ahead.
In the address to New Jersey, the President stated that he shall endeavor to take the ground he deemed most to the entire part of the country.
He stated that he had no malice towards any section. He stated that he shall do everything in his power to promote a peaceful settlement.
In this case, the purpose was to prepare legislators for the difficult decisions ahead and President Lincoln effectively uses the structure to connect the legislators' welcome of him now to the support they will owe him in the future.
Learn more about President Lincoln on:
https://brainly.com/question/26112254