Complex sentence: Founded by the Kassin family in the 1920's it was sold to the Bilkis and Schwartz families in 1977, and it remained in their hands until it was sold in 1988.
Split into simpler sentences: Founded by the Kassin family in the 1920s, it was sold to the Bilkis and Schwartz families in 1977. The camp remained in their hands until it was sold in 1988.