The Bill of Rights came to be included in the Constitution as a way to make people who leaned toward the Antifederalists more likely to accept the new Constitution. These people were worried about the power of the new federal government. They were afraid it would infringe on their rights the way the British government (they felt) had. Therefore, they were inclined to reject the Constitution and go back to something more like the Articles of Confederation. In order to allay these worries, the Federalist promised that they would consider a list of amendments as soon as the Constitution was ratified. These amendments eventually became the Bill of Rights.
The 3rd through 12th article of the bill of rights became the first ten amendments.
The 2nd article became the 27th amendment.