Constance and Her Companions – also known as the Martyrs of Memphis – devoted themselves to helping the sick and suffering during a deadly 19th-Century yellow fever outbreak in Memphis, Tennessee. In doing so, they lost their lives to the very disease they were trying to help others recover from.
Churches in the Worldwide Anglican Communion observe September 9th as a day to remember and celebrate their selfless commitment to help the sick and dying in the 1878 epidemic.
You can read a great article on the Martyrs of Memphis in Memphis Magazine.