From the developer's website:
Ride the rails to fun and adventure in Westward® IV: All Aboard, the fourth chapter in the thrilling real-time strategy franchise from Sandlot Games! Download Game and Play for Free!
When the patriarchal owner of the Turner Railroad Company goes missing, his children, Anne and Henry, are called upon to uncover the truth behind his disappearance. Protect the family business from greedy bandits as you help the Turners expand their railway to neighboring towns. Rescue kidnapped citizens being held for exorbitant ransoms, battle greedy bandits, and guide your town to fortune and prosperity in Westward IV: All Aboard!