Final answer:
The leaders of the Continental Congress in 1776 prioritized unity over addressing the issue of slavery in a moral and just manner.
Step-by-step explanation:
The phrase 'the signers of the Declaration of Independence chose unity over morality' means that the leaders at the time prioritized the unification of the states and the creation of a new nation over addressing the issue of slavery in a moral and just manner. Despite the clear contradiction between the principles of the American Revolution and the institution of slavery, the leaders of the Continental Congress in 1776 chose to ignore the issue in order to maintain unity among the states.