Final answer:
Anti-Federalists like George Mason and Patrick Henry opposed the Constitution's ratification due to the lack of a Bill of Rights, but their advocacy led to the promise and subsequent addition of the first ten amendments, ensuring the Constitution's ratification.
Step-by-step explanation:
During the ratification of the United States Constitution, Anti-Federalists were often wary of a strong central government and the lack of specific protections for individual rights. This group did not support the Constitution as it was originally presented, mainly due to the absence of a Bill of Rights.
However, certain key figures, such as George Mason and Patrick Henry, who were against the ratification, convinced their state conventions to support the Constitution with the condition that a Bill of Rights would be added immediately.
The promise to add a Bill of Rights was a critical factor in the Constitution's ratification in several states, including Massachusetts, Virginia, and New York, appeasing enough opposition to achieve ratification. James Madison played a pivotal role in drafting the amendments that would become the Bill of Rights, fulfilling a promise that helped to secure the Constitution's acceptance.
The inclusion of the Bill of Rights remains one of the most well-known and defended parts of the Constitution, ensuring fundamental rights and liberties to the citizens of the United States.