Complex sentence: The Treaty of Mendota was signed on August 5,1851 between the United States federal government and the Mdewakanton and Wahpekute Sioux of Minnesota near Pilot Knob on the south bank of the Minnesota River and within sight of Fort Snelling.
Split into simpler sentences: The Treaty of Mendota was signed on August 5,1851 between the United States federal government and the Sioux tribes of Minnesota (Mdewakanton and Wahpekute). The agreement was signed near Pilot Knob on the south bank of the Minnesota River and within sight of Fort Snelling.