From B.M. Newcomb's book:
At the outbreak of the War of the Revolution, Jacob Newcomb joined the patriot army, and died a martyr in the service, according to the church records of Lebanon, 1777. It is supposed that he died and was committed to a watery grave. His son, Bethuel, after leaving the service, set out in search of his father, Jacob, and traced him to Lake Champlain, but was unable to find further positive information concerning him. He learned that his father, sick of camp disease, with two other soldiers attempted to cross the lake in an open boat, but he could ascertain nothing additional.