Answer :
The Declaration of Independence was improtant to the American Revolution war effort because It helped unify the colonists to fight the war. Option D is correct.
The United States Declaration of Independence refers to the statement adopted by the Second Continental Congress meeting at the Pennsylvania State House ll) in Philadelphia, Pennsylvania, on July 4, 1776.
The Declaration announced that the Thirteen Colonies at war with the Kingdom of Great Britain baceme thirteen independent sovereign states, no longer under British rule.