Final answer:
North Carolina and Rhode Island were the two states that initially refused to ratify the Constitution, putting its ultimate success in jeopardy. The eventual inclusion of a bill of rights and the pressure from having other key states on board were critical in securing full ratification and ensuring the effectiveness of the Constitution.
Step-by-step explanation:
The two states that initially refused to ratify the Constitution, thereby putting its success in jeopardy, were North Carolina and Rhode Island. Both states had significant reservations about the Constitution, fearing the creation of a strong federal government that could potentially infringe on their rights and autonomy, echoing the recent experience of tyranny by the British Crown. These states, along with others like Virginia and New York, were wary of a Constitution that lacked a specific bill of rights to protect individual liberties.
The ratification of the Constitution was a complex process that involved debates between the Federalists, who supported a stronger federal government, and the Anti-Federalists, who feared such concentration of power. The promise to add a bill of rights was instrumental in securing the ratification from hesitant states. Eventually, even though the Constitution took effect after nine states ratified it, full effectiveness was uncertain without the support of all states, particularly the larger, wealthier ones.
The Federalists' campaign, arguments presented in papers, and assurances ultimately led to the successive ratification by New York and Virginia, and sometime later, North Carolina and Rhode Island. Notably, the Constitution probably would not have survived without the ratification by these key states due to their economic and political significance.