Complex sentence: There had been a few allotment programs ahead of the Dawes Act, but the vast fragmentation of reservations occurred from enactment of this act up to 1934, when the Indian Reorganization Act was passed.
Split into simpler sentences: There had been a few allotment programs ahead of the Dawes Act. However, the vast fragmentation of reservations occurred from the enactment of this act up to 1934, when the Indian Reorganization Act was passed.