Answer:
The event mentioned in the given is that of the Boston Tea Party.
The colonist seems to be pleased with the event as is stated "masters and owners are well pleas'd that their ships are thus clear'd, and the people are almost universally congratulating each other on this happy event."
Explanation:
The given excerpt is about the Boston Tea Party where American colonists revolted against the British government and dumped many crates of tea into the Boston Harbor. This event became the catalyst for the American Revolution.
The act of 'revolting' against the British empire by destroying the major source of tax and profit may have hurt the ones who were to profit from it. But for the colonist, it was a "happy event". This can be supported by the fact that "The masters and owners are well pleas'd that their ships are thus clear'd, and the people are almost universally congratulating each other.." This is enough proof of their happiness and satisfaction with what happened.