Molasses has had an interesting role in Boston history since the colonial days when colonists put molasses in their baked beans and inspired what we now call Boston Baked Beans.
In fact, according to the Boston Tea Party Museum, "John Hancock, made his fortune smuggling molasses on his ship called “Liberty”, the fortune which was later used to support the cause of American independence." Another use of molasses was in rum distillation, which was popular at the time in Boston.
Molasses was also responsible for one of the strangest man made disasters in Boston history, when in January 1919, a tank full of 2.3 million gallons of molasses from the Purity Distilling company collapsed in the North End. It resulted in a 15 foot tsunami (more devastating than a typical tsunami) going 35 miles per hour that destroyed buildings, swept people away, and eventually trapped people in a gelatinous state. 21 people died, and more than 150 were injured.
There is a distillery in Roxbury (Boston's first craft distillery) that along with other spirits, offers a rum named the Boston rum. They also offer tours.