The Southern Colonies developed as the demand for workers grew to clear land, construct homes and buildings, plant crops, and tend fields. Indentured servants and prisoners were shipped to the colonies to help fill this demand and earn their freedom. Maryland was founded by Cecilius Calvert to establish a safe place for Catholics. It was named for the English Queen and tobacco became a major crop, though farmers were also required to grow corn and raise livestock. Baltimore later became Maryland's largest city and port.