Complex sentence: In 1842 young Rolette put into a place a unique method of transportation between created a line of carts that ran on the Red River Trails between Pembina and the head of Mississippi navigation at Mendota, Minnesota.
Split into simpler sentences: In 1842 young Rolette put into a place a unique method of transportation. He created a line of carts that ran on the Red River Trails between Pembina and the head of Mississippi navigation at Mendota, Minnesota.