Individual rights were included in the constitution because

Individual rights were included in the Constitution because the writers of the Constitution wanted to protect the individual from their government and enshrine certain liberties and rights to make this process well defined. Following colonialism and the intrusion of the British Crown into many aspects of an individuals life the writers of the Constitution sought to prevent this from occurring in the soon to be formed Government of the United States. Enshrining individual rights was an essential goal of the Constitution. 

Because the rights of the constitution is only by bill.