What was one important argument against the proposed Constitution?

One important argument against the proposed Constitution was the lack of a Bill of Rights, which critics feared would leave individual liberties unprotected. Opponents, known as Anti-Federalists, believed that without explicit safeguards, the new federal government could become too powerful and infringe upon the rights of citizens. They argued that the Constitution concentrated too much authority in a central government, diminishing the autonomy of states and the rights of the people. This concern ultimately led to the adoption of the Bill of Rights as the first ten amendments to the Constitution.