What fundamental concern did Anti-Federalists have regarding the new Constitution?

The Anti-Federalists were primarily worried about the absence of a Bill of Rights in the newly proposed Constitution. Their fundamental concern was that the Constitution did not guarantee essential liberties and individual rights for the citizens. They feared that without explicit protections, the government would have too much power, potentially leading to tyranny and oppression.

The discussions around rights were pivotal during the ratification debates, with Anti-Federalists arguing that a clear declaration of rights was necessary to safeguard against government overreach. This concern ultimately led to the adoption of the Bill of Rights, which consists of the first ten amendments to the Constitution, designed to protect personal freedoms such as speech, religion, and the press, thus addressing the fears expressed by the Anti-Federalists.

While expansion of government control and issues related to taxation were concerns for the Anti-Federalists, the immediate and profound alarm over the lack of specific personal freedoms was central to their opposition to the Constitution before the Bill of Rights was introduced.