One of Spreckels' major contributions to the city of San Diego was his commitment to the construction of Balboa Park in preparation of the Panama-California Exposition. As the owner of the San Diego Electric Railway Company, he also developed a unique fleet of special streetcars that could handle the large crowds attending this event. Following the Exposition, the Class 1 streetcars would go on to provide a continuing public transportation service for the city of San Diego over the next 27 years.