SALEM, Ore. (AP) — The Oregon State Hospital has dedicated a memorial for the unclaimed remains of 3,500 people, most of them former patients at the state's mental hospital.

The dedication Monday comes a decade after lawmakers discovered the remains on a tour of the hospital. They were dubbed the "forgotten souls" and became a symbol of the nation's history of mistreating, neglecting and warehousing the mentally ill.

The memorial displays the corroding copper canisters that once housed the remains. They're stacked from floor to ceiling in a restored building where they were formerly locked away.

To protect the remains, the ashes have been transferred to new ceramic urns in a columbarium. Each person's name and birthday is on display.