The document provides an overview of the history and development of Wilmington, Delaware from the 18th century to the mid-20th century. It mentions the city's origins in shipping and shipbuilding on the Christina River. It then discusses the mills on the Brandywine River, the advent of railroads and trolleys, the influence of the DuPont family, and periods of unrest. The document also outlines architectural styles from the Classical period to Art Deco and how to interpret clues about a city's landscape and history from its historic markers, monuments, and building styles.