State bills of rights preceded the federal Bill of Rights. From June 1776, when the Virginia Declaration of Rights (the first state bill of rights) was adopted, until December 1791, when the federal Bill of Rights was ratified, eight states each adopted a bill of rights as a separate part of their state constitution. State constitutional rights existed even before there as a United States Constitution. Furthermore, the federal Bill of Rights contains provisions derived from earlier state bills of rights. Indeed, virtually every guarantee in the federal Bill of Rights can be traced to a similar guarantee in one of the bills of rights adopted in the states during the War of Independence or shortly thereafter. It is likely that the framers of the Constitution thought that the first bulwark of defense for the protection of the rights of citizens would be state bills of rights. One reason given at the 1787 Convention for not adding a bill of rights to the completed Constitution was that the state bills of rights remained undisturbed and were "sufficient" to protect against oppression by government.
Wilkes, Donald E. Jr., "First Things Last: Amendomania and State Bills of Rights" (1984). Scholarly Works. Paper 416.