Complex sentence: In 1836, the Chickasaw had reached an agreement that purchased land from the previously removed Choctaw after a bitter five-year debate, paying them $530,000 for the westernmost part of Choctaw land.
Split into simpler sentences: In 1836, the Chickasaw had reached an agreement that purchased land from the previously removed Choctaw after a bitter five-year debate. They paid the Choctaw $530,000 for the westernmost part of Choctaw land.