Final answer:
Delegates at the Constitutional Convention thought a Bill of Rights was unnecessary due to the government's checks and balances and the belief that listing rights would limit freedoms to only those mentioned. The Anti-Federalists' insistence on protections for individual liberties led to the eventual inclusion of the Bill of Rights.
Step-by-step explanation:
Many delegates to the Constitutional Convention believed that a Bill of Rights was unnecessary because the structure of the government itself, with its system of checks and balances, would be enough to protect individual liberties. They argued that specifically listing rights could be dangerous as it might suggest any unlisted rights were not protected.
Federalists such as Alexander Hamilton and James Madison claimed that since the Constitution did not abrogate existing state declarations of rights and given that the Articles of Confederation had not included a bill of rights, there was no need for a federal one. This belief was challenged by Anti-Federalists who feared a strong central government and demanded protections for civil liberties, leading to a compromise and the eventual drafting of the Bill of Rights.