As Mr. Perry said, best to do some research.My own ancestor served in a Flying Camp out of Frederick Co., MD. which was mustered in late Sept. or early Oct. for a 3 month tour, which was typical for the militia, joined Washington's Continentals at Harlem Heights, followed his retreat thru New Jersey, and were discharged somewhere near Trenton when the Flying Camps were dissolved on Dec. 1st, 1776. Washington offered extra incentives to the Flying Camps to stay on thru December, but it's recorded that most soldiers returned home when their enlistments expired. I, too, wonder if my ancestor was at the crossing of the Delaware and the Battle of Trenton, but have not found any documents to prove it.
Try to find : The captain's name. A muster roll of his company. As many pension statements as you can for the other soldiers in the company.