I have just begun reading a book on the Holiness-Pentecostal movement written by Vinson Synan.
http://www.amazon.com/dp/0802841031/...2T1_SC_3p_dp_1
There is a lot of history and documentation presented that the present holiness movements, really were begun by John Wesley and the Methodists. It also states that Brigham Young (one of the original Mormon leaders) spoke in tongues.... it is quite an interesting book. Not much mention is made of the UPC, but one small heading in one of the chapters. He interviewed Nathaniel Urshan for this book.
Seems like there are HUNDREDS of Pentecostal movements that have sprung up everywhere.