 Scriptural instruction and cohesion was aided by the work of Roberts in Birmingham, England in the 1860s and in the 1880s Thomas Williams in Chicago, Illinois.Both men traveled to local meetings edifying the brotherhood, and served as editors of The Christadelphian and "The Christadelphian Advocate" periodicals, respectively.Local statements of faith had been written by local congregations since the 1850s, but formal declarations of faith determining fellowship were not utilized until 1862–64, the years when Christadelphians began to change from an informal movement into a defined denomination.