Complex sentence: Sponsored by Luke P. Poland of Vermont, the Act redefined the jurisdiction of Utah courts, restricting the formerly powerful probate courts, which had taken no action concerning the 1857 Mountain Meadows Massacre, to their traditional jurisdiction.
Split into simpler sentences: Sponsored by Luke P. Poland of Vermont, the Act redefined the jurisdiction of Utah courts. It restricted the formerly powerful Probate Courts, which had taken no action concerning the 1857 Mountain Meadows Massacre, to their traditional jurisdiction.