Superb Revolutionary War-dated ALS, signed "B. Arnold,” one page, both sides, 8 x 13, September 16, 1780. Addressed from "Head Quarters Robinsons House" in West Point, New York, Arnold writes to his sister Hannah Arnold in Philadelphia only days before he would meet with John André to finalize his plans to turn the Hudson River stronghold of West Point over to the British. Additionally, he reports to his sister the safe arrival of his wife, Peggy Shippen Arnold (1760–1804), at West Point and inquires on his three sons who were in his sister's care.
In full: "I set down to answer your favor of the 4th Inst. which I have the happiness to receive by the hand of Mrs. Arnold three days since. She arrived here without Any Accident but very much fatigued as was the Dear Little Boy, who has a very sore head. They are both much reunited & Mrs. Arnold has an exceeding good appetite.
I am extremely unhappy to hear the Dear Little Boys in Maryland are discontented, but I cannot suppose as you seem to imagine that they are in want of the necessaries of Life. The Luxuries, I believe they have not, but I am assured by every Gentleman whom I have seen that has visited the School, that Mr. Booth keeps a plentiful Table of good plain Food. I hope they will have more prudence than to leave the School. I have no doubt of them being treated with kindness, then, but if they should continue to be Discontented I will remove them next Spring to some strict School.
Mrs. Arnold informs me it is very Sickly in Phild’a. I am very apprehensive for you and my Dear Henry,—the situation of my Family divided and at such a distance from each other is very disagreeable indeed. Mrs Arnold informs me there is a prospect of procuring the house that Mr. Allen owned. The situation is disagreeable but the house I believe is convenient. If it can be procured, I suppose Mr. Shippen will wish you to move the beginning of the next month.
Inclosed is a Letter for the D’r Boys in Maryland which I wish you to forward the first Opport’y, with any Articles they may write for which you think necessary for them. Give my tender love to my D’r Henry kiss him for me, & tell him a comfort He will write to me. Present my affectionate respects to all The Family at the Cottage, Mr. & Mrs. Bent, Mr. & Mrs. Meade & Compl’ts to all Friends." Arnold adds a short postscript, "The Linen of Mount Vincent from McPherson to son James Mrs Arnold tells me is in the closet in Her Chamber. I wish you to look for and give it to Mr. Shippen." In very good to fine condition, with somewhat irregular gray toning over the first few lines of text (not affecting readability), a couple of trivial old mounting remnants on the second page, and stamps of the Mercantile Library and Tomlinson Collection at the bottom of the second page.
On September 21, 1780, Arnold met with the British emissary John André and made the final arrangements to deliver his command at West Point to the British. Two days later, however, the plot was discovered when André was caught carrying incriminating papers by New York militia near Tarrytown. Upon hearing the news, Arnold boarded the HMS Vulture and fled to General Clinton in New York City on September 25th. The 31-year-old André was not so fortunate; he was tried and hung as a spy on October 2nd.
When General Washington arrived in West Point, he reportedly encountered a hysterical Peggy Shippen Arnold, who emphatically denied any knowledge of her husband's plot. She returned to Philadelphia with her infant child, but on October 20th the authorities banned her from the city, and she crossed the lines to New York to join her spouse. Arnold was never handsomely awarded nor was he honored by the British. He received a brigadier general's commission and led an expedition into Virginia in late 1780. After the war, he pursued a failed mercantile business in New Brunswick and spent the remainder of his life in London. Letters and documents written and signed by Arnold from the eve of his treason in September 1780 are rare and highly desired.
Provenance: The Marshall B. Coyne Collection.

Format:ALS