According to the National Archives, Supreme Court cases are archived as far back as 1772. However, the bulk of the existing archives available for public consumption were archived between 1790 and 1984.
Since the Supreme Court's primary duty is to interpret the law as it relates to the U.S. Constitution, all cases are carefully recorded and maintained for reference by smaller courts and individuals who are looking for assistance in applying the law to similar cases. Another essential purpose for archiving Supreme Court case records is the impact some decisions have had on the Bill of Rights, fundamentally altering the law's interpretation. Requests for archived records can be made through the National Archives.