"Joel Sanford … enlisted as a 'levy' in 1780, in the 'Eighth Connecticut regiment,' his term expiring December 3, same year. He enlisted second in Captain James Stoddard's company, General Waterbury's State brigade, September 10, 1781. He was killed in action February 8, 1782.
Given the date of death, it seems much more likely that he died in camp of smallpox or some other disease. Active fighting had ceased as of the Surrender at Yorktown, 19 October 1781.