Why did the American states add the Bill of Rights to The Constitution in 1791?

Why did the American states add the Bill of Rights to the Constitution in 1791?  Specifically what did they fear?  Is there still possible reason to fear that in 2022 America? What is a specific interest you think some states do not protect well…or that you believe some STATES are trying to deny to people now. Explain why you think it is an interest that should be protected by the state governments. What can/should people do at the STATE level to change what is happening in government regarding that interest?