The Supreme Court's online brief collection includes joint appendices beginning in January 1979, with some selected joint-appendix coverage dating back to 1936.
Notes on verification
General timeline (regular online coverage from ~1979, selected historical materials back to 1936) is corroborated by law library guides, but exact month (January vs. October 1979) on the Court's own page could not be independently verified. [tier=bronze indep_score=0.49 clusters=2 claim_tier=notable]
Sources
- Where to Find Briefs of the Supreme Court of the U.S. (seed:politics_and_current_events)
- https://guides.law.stanford.edu/c.php?g=676062&p=4764062 (corroboration)
- https://guides.brooklaw.edu/Supreme_Court/briefs (corroboration)