Complex sentence: The federal government believed that because the value of land surrounding railroads would increase as much as twofold, granting land to private railroad companies would theoretically pay for itself and also increase the transportation infrastructure throughout the nation.
Split into simpler sentences: The federal government believed that the value of land surrounding railroads would increase as much as twofold. Therefore granting land to private railroad companies would theoretically pay for itself and also increase the transportation infrastructure throughout the nation.