Command of the patriot forces in the northern theatre was given to Horatio Gates. Gates asked Arnold to serve as commodore of a fledgling, makeshift fleet of armed continental vessels on Lake Champlain. Gates regarded the fleet's current commander as lazy and incompetent, and Arnold leaped at the opportunity to replace him.
Toward the end of July 1776, word reached Gates and Arnold that the Continental Congress had officially declared independence from Great Britain. No longer were the colonies fighting for the rights as Englishmen, they were now fighting for their independence as a separate nation - the United States of America. Unfortunately for Arnold, this period consisted of more than just the exciting news of the Declaration of Independence. Accusations had surfaced regarding his conduct in Canada shortly before he was promoted to brigadier general. Now, those accusations were intensifying and reaching a broader audience with the court-martial of several senior officers in the northern army. Gates tried to assure Arnold that his reputation would be secure, and urged his subordinate to focus on his efforts at Champlain. Over time, however, the accusations did not abate, and Gates himself became a critic.
Commodore Arnold proceeded to refit the existing Champlain fleet. And he built new vessels from scratch. Despite his best efforts, his 17-ship fleet remained inferior to anything the British could put to sea, and Arnold knew it.
Arnold soon learned of the fate of American forces in Long Island. Details were sketchy, but he became aware of the fact that the British had Washington's decimated army on the run and were in complete command of New York City. Now, Arnold's defense of Lake Champlain was all the more critical. If the British could capture Lake Champlain and Fort Ticonderoga, the Americans could lose the entire northern theatre to the British. If they could also defeat the army under Gates as they had apparently done so with Washington's, it would effectively end the American Revolution.