Complex sentence: By the 1830s, the Brothertown Indian Nation had sold its land to the state of New York and purchased land in Wisconsin, where the 3200-member tribe thrives in twenty-first century America.
Split into simpler sentences: By the 1830s, the Brothertown Indian Nation had sold its land to the state of New York and purchased land in Wisconsin. The 3200-member tribe thrives in twenty-first century America.