Complex sentence: They formed the Moraga Land Association and planned to build a railroad and to subdivide the property into town sites and small ranches, but the plan never materialized and Carpentier foreclosed on the property.
Split into simpler sentences: They formed the Moraga Land Association and planned to build a railroad and to subdivide the property into town sites and small ranches. But the plan never materialized, and Carpentier foreclosed on the property.