Insular Cases

The Insular Cases are a series of opinions by the U.S. Supreme Court in 1901, about the status of U.S. territories acquired in the Spanish–American War. The Supreme Court held that full constitutional rights do not automatically (or ex proprio vigore—i.e., of its own force) extend to all places under American control. This meant that inhabitants of unincorporated territories such as Puerto Rico—"even if they are U.S. citizens"—may lack some constitutional rights (e.g., the right to remain part of the United States in case of de-annexation).