The year in which the article or book was published or the year of the interview in which Patrick Doonan said those words must be added, so that the reader has a reference to look up the quotation in case that he wants more information.
Also, more information about the author can be added, although it is not necessary to follow the rules of quotations, it helps to justifiy the use of that specific quote.
The significance of the conflict was that the Hessian army crushed in Washington's raid across the Delaware River and the Americans were invigorated by the easy defeat of the British Hessian forces.
