The following is extracted from Jayne Pratt Lovelace's 1980 book, "The Pratt Directory" page 55::
(Asa) Resided at Dublin, NH and enlisted 7 Dec 1776 at Springfield, Ma. Discharged 23 Mar 1777. Returned to Dublin. Volunteered again Apr/May 1777. Discharged at Mount Independence near Ticonderoga. Drafted July 1777 for three months. In Battle of Bennington. Present at West Point when Major Andre was executed.
Starting here I am going to indulge myself in a long-winded analysis of the above brief summary to flesh out the story of our ancestor's service in the Revolutionary War as best I can. Follow along or ignore it as you wish.
First inquiry: How would he have gotten to Springfield, Massachusetts from Dublin to volunteer? The answer to me is obvious being somwhat familiar with New England geography. He would have gone west to the Connecticut River and then south by boat to Springfield. I used Google Map driving directions to learn that Brattlesboro, Vermont, on the river, is about 30 miles west of Dublin via Route 101 and Route 9. Today's New England roads mostly follow the routes of Colonial roads (that often followed Indian trails that in turn may have followed ancient game trails).
The driving distance from Brattlesboro to Springfield is about 60 miles. Of course it was a far longer distance for him going downstream by boat on the meanders of the river. He probably would have been on a boat like those the Bartrams rode on when going up the Mohawk River; long, open, double-ended craft with an auxiliary sail which were rowed downstream and poled upstream.
Picture if you can; our ancestor Asa, 19 years old and without doubt leaving home for the first time, dressed in what they wore for winter in those times, on horeseback or in a horse-drawn wagon, carrying a musket and maybe a big knife, with some kind of pack or duffle and some food prepared by his mother for the start of the trip, heading west for the river, eager but probably a little scared.
The nexr inquiry: Why did Asa go to Spingfield and enlist in Decmber of 1776 only to return to New Hampshire in March of 1777? What I know about this period and place is that General Washington had designated Springfield as the National Armory and that in the fall of 1776 the Americans were taking a beating in what is now new York City. Washington had to abandon Manhattan Island and retreat across the Hudson. Perhaps that precipitated a call for troops to come and defend the site of the National Armory. But in December the tide turned after Washington crossed the Deleware and defeated the Hessions at Trenton, New Jersey, and in January 1777 defeated the British at Princeton. These twin victories may have been perceived to lessen the threat to Springfield so the New Hampshire boys could be allowed to go home. If you have another theory I would like to hear it.