The Insular Cases are SCOTUS cases regarding rights of people in U.S. territories. They’re considered U.S. citizens from birth, but they don’t have the same constitutional rights or representation as citizens who live in one of the 50 states.
Research:

Behind the Scenes Minis: Piece of Work
17:48

E. Virgil Neal: Hypnotist, Fraudster, Tycoon, Part 2
41:22

E. Virgil Neal: Hypnotist, Fraudster, Tycoon - Part 1
35:28