What are the three states that ratified the constitution in 1787?

  Delaware, Pennsylvania, and New Jersey

All three of those states ratified the US Constitution in December, 1787. Delaware's state legislature was first to ratify, on Dec. 7. Pennsylvania's legislature ratified on Dec. 12, and New Jersey on Dec. 18.  In Delaware and New Jersey, the vote in each state legislature was unanimous in support of ratification of the Constitution.  In Pennsylvania, the state legislature voted 46 to 23 in favor of ratification.

Support for ratification followed closely in Georgia and Connecticut. Georgia's legislature voted unanimously for ratification on January 2, 1788.  Connecticut's legislature voted 128 to 40 in favor of ratification on January 9.

By the spring of 1788, the required 9 of 13 states had ratified the Constitution.  Ultimately, all 13 state legislatures did vote in favor of ratification, though the margin was close in some states.  

explanation:

actually, not all representation was acceptable based on this little piece of article, in 1776, the second continental congress issued the declaration of independence, stating their specific grievances with the british monarchy and why they were going to create a separate government. after the colonies separated from the british monarchy and formed the united states of america, they had to answer some crucial questions: 1) if not a monarchy, what type of government was the united states going to have? 2) what kind of government was going to protect the people without violating their individual liberties?