Benedict Arnold’s Daybook

Gen. Benedict Arnold’s 1778–79 daybook is one of the most intriguing documents of the Revolutionary era held in the collection of the Pennsylvania State Archives (Record Group 4.15). In its pages, Arnold kept a record of receipts and expenditures during his military campaigns in the American Revolutionary War and his tenure as military governor of Philadelphia.

Arnold was one of the most successful Continental Army field commanders in the early years of the war. Gen. George Washington himself admired Arnold’s personal bravery, aggressiveness and skill as a battlefield commander. In 1778 Arnold was appointed military governor of Philadelphia after the British withdrew from the city following nearly nine months of occupation. In 1779 he married Margaret “Peggy” Shippen, who was from a wealthy Pennsylvania family with Loyalist leanings. Arnold augmented his military pay with various business ventures, several questionable, garnering negative attention from politicians in Pennsylvania.

Urged by Pennsylvania’s Supreme Executive Council president, Joseph Reed, Arnold was brought up on four charges by the Continental Congress in 1779. Most dealt with alleged improprieties while he was military governor. At his court-martial from December 1779 to January 1780, Arnold was found guilty of two of the four charges. The first was that he gave permission for a vessel in Philadelphia to clear port when it was closed. Arnold had a personal investment in the ship and its cargo. The other charge concerned his private use of public wagons to remove private property in danger of falling into the hands of the enemy. Arnold was sentenced to be reprimanded by Washington.

Arnold’s daybook consists of pages that appear to have been torn out of a bound volume. Two leaves, equaling four pages of text, have been missing since 1987. It is believed that those pages were likely taken by an individual who committed a series of thefts at the State Archives and other repositories in the mid-1980s. As it exists today, the daybook starts on page 3 with the date July 15, 1778. The missing page 1 began with an entry for October 1777. The document ends with page 18, dated November 10, 1779. This is only one month prior to the start of Arnold’s court-martial.

The document reveals significant details about Arnold’s conduct at the time, such as his curious relationship with merchant and politician Silas Deane. After being discredited by the Continental Congress because of financial discrepancies while serving as an emissary to France, Deane returned to America to defend himself before Congress. Although Deane had become a public pariah due to the bad press, Arnold welcomed him into his home while he was visiting Philadelphia, as described on page 3. A number of payments to Deane are also recorded in the daybook.

Page 4 describes various ships that Arnold partly owned while in military service, including the schooners Charming Nancy and General Arnold and the sloop York, related to the first charge at his court-martial. An entry on page 13 lists Arnold’s payment to Capt. James Duncan for the expense of luxury goods Duncan purchased in British-occupied New York City, which in turn were sold for a profit to fill Arnold’s personal coffers. This was done at a time when Arnold had closed the shops in Philadelphia to stop profiteering.

As military governor of Philadelphia, Arnold began purchasing household items such as knives, forks, dishes and tables, described on page 15. He also began buying significant amounts of food and drink and hired maids and cooks.

Arnold’s initial disenchantment with the Patriot cause was due in part to his belief that he had been disrespected by not being adequately rewarded with a promotion to major general in a timely fashion and to Congress’ hesitation to reimburse him for all the expenses he claimed. He later defected to the British, agreeing to turn over fortifications at West Point in exchange for money and a commission as a brigadier general in the British Army.

After Arnold’s traitorous plans at West Point were exposed, his former revolutionary compatriots began to castigate him. Washington sought to have Arnold returned from the British in exchange for various prisoners and later supported a kidnapping attempt, which was unsuccessful. On October 2, 1780, Arnold was declared a traitor and two days later the Continental Congress passed a resolution erasing his name permanently from the army register. By November 13, 1780, his estate, Mount Pleasant, just outside of Philadelphia, was deemed forfeited by Pennsylvania’s Supreme Executive Council. It was sold by the commonwealth on June 6, 1781, for £850.

Arnold’s daybook may have entered state hands in one of three ways. Arnold may have submitted it to the Continental Congress as proof of his claimed expenses; or it may have been collected as evidence in Arnold’s court-martial for improprieties while he was military governor of Philadelphia; or perhaps it was seized on September 28, 1780 — four days after Arnold fled to British lines — when his papers and home were judged to be forfeit after his traitorous action became known. The document was evidently in the possession of the commonwealth by 1874, when it was first cited in print by John B. Linn in Potter’s American Monthly. Linn believed the latter of the three scenarios to be the most likely one.

Richard C. Saylor is an archivist for the Pennsylvania State Archives and author of the award-winning book Soldiers to Governors and numerous articles on military, political and sports history.