What convinced many Anti-Federalists to support the Constitution?
There had been very influential voices among those agitating for secession from Great Britain and for the formation of a new nation who looked warily at the Constitution that was put forward at the Constitutional Convention. Some of those voices had not been delegates, but were powerful advocates of both independence and of a relatively weak central or federal government. Unsurprisingly, these voices emanated from the southern colonies, which is not noted for purposes of denigrating them. On the contrary, Thomas Jefferson, who had been until very recently among the most revered figures in American history, and Patrick Henry were both skeptical of the long-term implications of the draft of the Constitution on which they were expected to pronounce their support. Their concerns centered on the absence in the Constitution of a series of provisions that would explicitly confirm the limitations of the federal government. This series of provisions was referred to as the “bill of rights.” In one of his letters to James Madison, one of the principal authors of the Constitution, Jefferson reiterated his strong opposition to any constitution that did not safeguard against an excessively powerful and intrusive federal government:
“There are other good things of less moment. I will now add what I do not like. First the omission of a bill of rights providing clearly & without the aid of sophisms for freedom of religion, freedom of the press, protection against standing armies, restriction against monopolies, the eternal & unremitting force of the habeas corpus laws, and trials by jury in all matters of fact triable by the laws of the land & not by the law of nations.”
Madison assured Jefferson, Henry and other so-called anti-Federalists that, upon ratification of the underlying document (the pre-amendment Constitution), a Bill of Rights along the lines of that envisioned by Jefferson would be added. Madison’s guarantee was sufficient to convince most of the influential anti-Federalists that the final product—the Constitution as amended by the Bill of Rights—would meet their requirements for ensuring limits on federal power.
The main thing that convinced many (but by no means all) of the Antifederalists to support the new Constitution was the addition of the Bill of Rights. This alleviated the fears of many of the more moderate Antifederalists.
Antifederalists were very wary of the power of the federal government. They had been relatively happy with the system that the Articles of Confederation had created. They felt that the federal government was much more likely to abuse the rights of the people than the state governments would have been. They worried that the federal government might, in the future, become like the English government. Because it was less closely connected to the people, it might start acting for the benefit of national elites and forget the rights of the people in the states.
The Federalists could not completely convince the Antifederalists that this would not happen. However, they did promise to amend the Constitution to include what we now call the Bill of Rights. The Bill of Rights would explicitly protect the freedoms of the people from the national government, thus making it less likely that the national government could abuse people in the way that the Antifederalists feared.
By adding the Bill of Rights, the Federalists managed to convince enough Antifederalists to support the new Constitution and the document was ratified in 1789.