Complex sentence: The reservation originally covered 1,300 square miles (3,400 km²), but much of the community's land was improperly sold or seized by outside interests, including the U.S. federal government, in the late 19th century and early 20th century.
Split into simpler sentences: The reservation originally covered 1,300 square miles (3,400 km²). Much of the community's land was improperly sold or seized by outside interests, including the U.S. federal government, in the late 19th century and early 20th century.