Forced Quarantine Detention has been on the books for many years. Federal law allows quarantine to prevent entry of infectious diseases into the US, and to prevent the spread across state lines. The last large scale Federal use of quarantine was for Spanish Flu in 1918. See the CDC page on Legal Authorities for Isolation and Quarantine .

Diseases must be added by executive order to the list for which quarantine is authorized. The executive order you are probably thinking of actually added pandemic influenza to the list. Viral hemorrhagic fevers (such as Ebola) had been on the list since 1983. See Q & A on the Executive Order.

States can use quarantine to prevent the spread of disease within their borders. Most states already have such laws on the books. See State Quarantine and Isolation Statutes. For example, see Texas.