Along with Fort Scammell on nearby House Island, Fort Preble was built to deter attack by a hostile power in the event the United States was considered a belligerent in the ongoing conflict between Great Britain and Napoleonic France. In October 1808, Dearborn ordered a company of the Regiment of Light Artillery under Captain Joseph Chandler to occupy the fort and instructed them to do whatever was necessary to enforce the Embargo Act against embargo-breaking ships. The embargo was an attempt to punish Britain and France for actions against US shipping by prohibiting exports to them; it cut off much of New England's income and was highly unpopular. The embargo was finally lifted in March 1809 when President James Madison took office, but the situation eventually led to the War of 1812.