Brethren vs. United Brethren

My Wife used to attend a Grace Brethren Church. I have co-workers who attend a United Brethren Church. Apparently these two Protestant Churches are not the same, but both promote the pre-millennial rapture or what is sometimes referred to as Dispensationalism (popularized in the late 1800’s by a Plymouth Brethren by the name of John Darby).

It is my understanding that the former spun off from the Anabaptists in Europe. It’s founder was a former Catholic Priest.

The latter spun off from the Mennonites of Pennsylvania. The father of the famous Wright Brothers was a Bishop in United Brethren Church. There was a split and he was on the side that remained and the other side joined with the Methodist Church to form the United Methodist Church.

Have any of you ever been a member of or know someone who has been a member of either the Brethren or the United Brethren Churches? I enjoy learning about what others believe and why they believe it. God Bless.