They were sometimes referred to as the "York Brethren or Yorkers", because most of the members in 1843 were located in York County, Pennsylvania. This group believed the majority of the River Brethren churches were becoming too lax in their standard of Biblical non-conformity and non-resistance, and desired to return to older, Scriptural doctrines and traditions. With the increase of more progressive and modernizing groups in Christendom following the industrial revolution, and the emergence of clarifying naming of other traditional Old Order groups among the plain people such as Amish (Old Order Amish forming 1862–78), the Mennonites (Old Order Mennonites, 1872–1901) and the German Baptist Brethren (Old German Baptist Brethren 1882) in the late 1800s they defined themselves also as "Old Order".