The Short Version
The claim is broadly accurate. U.S. adverse possession laws do allow a person to gain legal ownership of property by occupying it without the owner's permission for a state-defined statutory period. However, the claim simplifies the doctrine: courts also require that possession be open and notorious, exclusive, and continuous — and some states impose additional conditions like paying property taxes. Statutory periods vary widely (5–30 years) across jurisdictions. The core proposition is correct, but the framing omits important legal requirements.