Complex sentence: After the state of Nebraska was admitted into the Union the state government extinguished the tribe's rights to their land, soon selling it and using the proceeds of the sale to defray the expenses to obtain other lands for the Indians elsewhere.
Split into simpler sentences: After the state of Nebraska was admitted into the Union, the state government extinguished the tribe's rights to their land. It soon sold the land and used the proceeds to defray expenses to obtain other lands for the Indians elsewhere.