The Philadelphia Lazaretto was the first quarantine hospital in the United States, built in 1799, in Tinicum Township, Delaware County, Pennsylvania. The site was originally inhabited by the Lenni Lenape, and then the first Swedish settlers in America. The facility predates similar national landmarks such as Ellis Island and Angel Island and is considered both the oldest surviving quarantine hospital and the last surviving example of its type in the United States. All passenger and cargo vessels entering the port of Philadelphia were required to dock at the Lazaretto for inspection. Passengers suspected of contagion were quarantined in the hospital, and all suspect cargo was stored in the public warehouse. The Board of Health of the City of Philadelphia operated the facility and enforced the local quarantine regulations until the Commonwealth of Pennsylvania assumed authority for enforcing quarantine regulations in 1893. After it was closed as a hospital, it was used as an aviation base.