 He also founded a girls' school for the Osages, placing it under the care of the Sisters of Loretto.In August 1855, he established his episcopal see at the prosperous city of Leavenworth in order to better minister to the growing number of white settlers there.As the number of churches and schools increased, Nebraska was formed into a separate vicariate in 1857 and the Kansas Territory was left under Miège's jurisdiction.