Roughly 80,000 people sit in solitary confinement in U.S. prisons and jails on any given day, locked in cells the size of parking spaces for 22 to 24 hours daily, often for months or years. Prison officials call it "administrative segregation" or "restricted housing" and use it for discipline, protection, or gang management. People in solitary lose access to programs, education, and most human contact. Studies link prolonged isolation to hallucinations, paranoia, depression, and lasting psychological damage. The United Nations calls solitary beyond 15 days torture. Yet U.S. prisons routinely hold people in isolation for years—sometimes decades. Albert Woodfox spent 43 years in solitary at Louisiana''s Angola prison before courts freed him in 2016. Litigation challenging solitary under the Eighth Amendment''s ban on cruel punishment has produced mixed results. Some states reformed their practices after lawsuits, limiting solitary for juveniles, pregnant women, or people with mental illness. But most prisons still use isolation extensively, with minimal oversight and few restrictions on how long people can be held.