Silas Deane was born December 24, 1737 at Ledyard, CT, son of Silas Dean (sic), a blacksmith and land speculator, and Sarah Barker Dean, formerly of Marshfield, MA. Following his graduation from Yale College in 1758 he taught school in Hartford while reading for the bar. One of his pupils was Edward Bancroft, later the notorious doctor turned British agent, who served as Secretary to the American Commission in Paris. In the course of settling the estate of Joseph Webb of Wethersfield, he met and married his widow, Mehitabel, in 1763. They had one son, Jesse. After she died in 1767 Deane married in 1770 Elizabeth Saltonstall, granddaughter of a governor and daughter of a general. Through his marriages Deane assumed quickly an established financial and social position in Wethersfield. He pursued his legal profession but was engaged chiefly as a merchant and West Indian trader.

Deane was active in his community's church and represented Wethersfield for several terms in the Connecticut Assembly. He participated enthusiastically in the protest movement against British commercial policy. He was secretary of the Connecticut Committee of Correspondence and attended meetings and conventions which discussed ways of expressing the colonies' complaints. In 1774 the Connecticut Committee of Correspondence appointed Deane, Roger Sherman and Eliphalet Dyer as delegates to the Continental Congress in Philadelphia. In this position Deane served on 40 committees, being especially effective on the naval committee and as chairman of ways and means. He disliked his fellow delegate, Roger Sherman, and their incongeniality later hurt Deane as Sherman opposed him politically. During the recess, December 1774- 1775 Deane and some associates gave their personal financial backing to the daring capture of Fort Ticonderoga.

Delegates to the Continental Congress in the fall of 1775 were elected rather than Appointed and Sherman's organization defeated Deane. He had made such an impression in Philadelphia, however, that he was chosen by the Committee on Secrecy as Congress' agent to France to procure supplies and by the Committee on Secret Correspondence to promote a treaty of alliance. He departed March 16, 1776 and arrived at Bordeaux in May. In addition to his official duties, Deane had private business assignments with the Morris, Willing Company of Philadelphia and for his own family enterprises. Deane was to purchase supplies and materiel for Congress with money or credit from the sale of American commodities in Europe. He was to receive a commission of 5%. With no contacts and speaking no French it was a daunting situation which only an energetic and resourceful entrepreneur like Deane would attempt.

He established a relationship with Hortalez and Cie, a firm devised by the French government and headed by Caron de Beaumarchais, the dramatist, to aid the colonies, ostensibly privately. Deane through this and other deals managed to ship supplies and guns to Portsmouth, New Hampshire, where they arrived in time to assure the victory at Saratoga. This in turn convinced the French to sign a treaty of alliance. Congress had created an American Commission at Paris to supercede its individual agent. Deane was named a Commissioner along with Benjamin Franklin who arrived in September and Arthur Lee of Virginia and London. Deane and the others signed the treaty of alliance Feb. 6, 1778. Meanwhile Deane's enemies in Congress and the friends and family of Arthur Lee, his antagonistic fellow commissioner in Paris, demanded his recall March 4 to report on the situation in Europe and account for funds spent. Deane would have preferred to postpone his return but on the advice of Franklin sailed on D'Estaing's flagship with Conrad A. Gerard, the first French minister to the United States, arriving in Philadelphia July 11, 1778.

Congress then proceeded to ignore Deane's efforts to meet and make his report and present his accounts for payment. He had used many of his own funds for the government's business and commissions were owed him, but he was thought to have misused government funds for his own interest. As time passed and Deane became aware that his enemies in Congress were humiliating him, he grew impatient and wrote a public statement which was taken up by the press. This was resented by Congress. During the year in which Deane waited on Congress he was nominated for a seat in the upper house of the Connecticut legislature but did not serve. In August 1779 Congress offered him $10,000 in depreciated currency which he refused. He determined to return to France to collect the vouchers needed to substantiate his claims. After attending to family commercial business in Virginia, he returned to France in March 1780, a private citizen.

In Paris Franklin was supportive and hospitable and Deane prepared his accounts, but again, Congress delayed reviewing them. Thomas Barclay, the Consul at Paris, was appointed by Congress to the task but claimed he had not the authority to settle them. Deane moved to Ghent to save money and avoid imposing on Franklin. His health and his fortunes deteriorated and his morale suffered keenly at the frustration of the delays. Eventually he moved to England and lived for a while on the charity of friends, among them Dr. Edward Bancroft, the erstwhile secretary of the American Commissoners in Paris, whose role as a double agent for the British was not revealed until about 1870. Deane received discouraging reports from friends at home, Robert Morris among them, about the almost total erosion of the currency and the fiscally irresponsible Congress. In his own despondency he came to think a negotiated settlement of the war was advisable and wrote in this vein to friends, perhaps conniving at the interception of the letters by the British. They were published by the Tory publicist in New York, Rivington, and caused an outcry of treason. In 1867 published correspondence of Lord North and the King describes a suggestion of a bribe, but no evidence has come to light that it was actually offered or taken. Deane denied it later. At the nadir of his fortunes and perspective on the war, Deane was unaware that with the intervention of the French navy the military balance changed quickly and, as the Rivington letters appeared, Cornwallis's, surrender was imminent.

Deane longed to return home but his loyal brother, Barnabas, warned he would not be accepted at that time. Remaining in London, Silas Deane explored many ideas for the promotion of post-war Anglo American commerce. Of special interest was a scheme for a canal between the St. Lawrence and Lake Champlain which he discussed with Lord Sheffield and Lord Dorchester (Guy Carleton), the Governor-General of Canada. Full of hope for such prospects he borrowed money to board ship at Deal September 23, 1789. But before sailing, he suffered a violent abdominal attack which caused a paralysis and death after a few hours. Suspicions of poisoning by Dr. Bancroft, an authority on poisons, have not been proved. He was buried at Deal. Barnabas later thanked and reimbursed a kind American, Theodore Hopkins, who attended to the interment of the body. His son, Jesse Deane, was to recieve from London in 1795 proceeds from the sale of a diamond encrusted gold snuff box of his fathers.

Silas Deane's granddaughter and only heir, Philura Deane Alden and her husband, Horatio Alden of Hartford, prepared in 1835 a Memorial to Congress documenting his claims for money owed him by the government. The Memorial contains accounts and important documents such as Lafayette's commission. In 1842 both houses awarded the heirs $37,000, a partial restitution, and described the original audit by a Congressional Committee under the chairmanship of his old enemy, Arthur Lee, as "ex parte, erroneous and a gross injustice to Silas Deane".