His relations with Congress deteriorated, and his critics succeeded in forcing a congressional investigation. That investigation resulted in a recommendation for court-martial. Washington, not wanting to destroy the career of one of his most promising generals, issued a reprimand. That reprimand stung Arnold, who bitterly complained to his commander-in-chief about the ingratitude he, "a cripple in the service of my country," was forced to endure.
Faced with financial ruin and a devastated reputation and, no doubt, under the influence of his new Tory wife, 19-year old Margaret Shippen, Arnold made his fateful decision. He would return his loyalties to the Mother Country, and seek fame and fortune in the King's service.
In September 1780, Washington appointed Arnold, at the latter's request, to command the garrison at West Point, New York. Arnold had already established secret communications with the British earlier, and now he offered to deliver the West Point garrison to the British for a sum that today would equal roughly $1 million. Arnold's carefully crafted plan would unravel with the capture of British Major John Andre, Arnold's principal British contact. When Arnold heard of Andre's capture, he made quick his escape, fleeing from West Point hours before the arrival of Washington. Arnold's wife performed a convincing emotional breakdown before General Washington, winning the commander-in-chief's sympathies and escaping any retribution for her husband's treason. It was, however, an act. Before long, Margaret would re-join her husband.
Reaction from the American colonies was swift and severe. He was bitterly derided across North America. For his part, Washington was virtually devastated. "Arnold has betrayed us," moaned the general-in-chief. "Who can we trust?"
Benedict Arnold was now a brigadier general in the King's service. James Thomas Flexner writes: "Arnold served George III with the same skill and daring he had shown in the Patriot cause." Indeed, General Arnold led devastating raids on American supply depots in Virginia and Connecticut. He looted patriot towns and villages, burned ships, destroyed grain and munitions, and wreaked general havoc on the civilian population in his areas of attack. In fact, his actions toward American civilians would result in some of the harshest condemnations of his character, following his treason.
In retrospect, Arnold's fervor is not difficult to understand. Benedict Arnold had thrown himself into the American cause with enthusiasm. He had conducted himself with valor and dedication, becoming one of the Continental Army's most innovative and resourceful leaders. Yet he disdained the lack of support provided by Congress, and became disillusioned at the lack of commitment on the part of the American people overall. He especially resented the "ingratitude" of those he labored for and with. And he bitterly detested those who had run down his reputation and interfered with his social, military and business achievements. In the end, Arnold grew to despise the American Cause that he had so earnestly committed himself to.
