The most critical documents and evidence to establish territorial jurisdiction include signed contracts containing forum selection clauses, business records demonstrating the defendant's deliberate in-state commercial activities (e.g., invoices, shipping records, or targeted marketing materials), digital evidence like website interactivity and geolocated user agreements, corporate filings indicating registered agents, and affidavits detailing the defendant's physical presence—all serving to prove the defendant purposefully availed itself of the forum state under the minimum contacts test.
