Born in Dublin, Ireland, Nicola had been an officer in the British Army, serving in Europe before immigrating to the Thirteen Colonies.

When the American Revolution broke out, Nicola offered his services to the colonial government, which eventually appointed him to various positions with local forces.

In 1782, after the end of most hostilities but before the signing of the Treaty of Paris, Nicola wrote the Newburgh letter, which was received coldly by Washington.

[6] At the start of the next year, Nicola decided to quit the dry food business for good and focus more on writing, stating "[Magazines were] the taste of the age, and found to possess many conveniences, such as gratifying the curiosity of the public, and serving as a repository for many small, though valuable pieces that would otherwise be lost to the world.

[4][9] In July 1775, Nicola was hired by the Pennsylvania Council of Safety to inspect the local defenses in place along the banks of the Delaware River.

[10] While attaining that position (which he was granted in February), Nicola composed and presented to the Council of Safety a "Plan of a Powder Magazine" and saw to the repair of the city jailhouse, for which he was reimbursed $226 by the Continental Congress.

In March 1777, Nicola proposed to the Continental Congress the formation of an "Invalid Corps," a group of men unfit for combat but still able to perform other military duties.

[1] The Invalid Corps was stationed in Philadelphia for most part of the Revolutionary War, but it was forced to move once General William Howe advanced into the city in 1777.

[14] Due to sickness, lack of clean water, and worries about British incursions, it was recommended to Nicola that he move the Corps to Trenton, New Jersey.

[14] After a brief period in the camp of Valley Forge in the spring of 1778, the Invalid Corps moved back to their original quarters at Philadelphia, just after the British evacuated from it.

[18] Following the drawing of "Plan", Nicola submitted two papers where he obtained information from the British to Congress: "A Scheme for a Partisan Corps" and "Judicious remarks on a proposed reformation in the Army".

[20] Washington, who did not show any favoritism to either, sent both series of letters to General Alexander McDougall and asked the court in West Point to settle the matter.

In October 1777, Nicola sent out an arrest warrant for Sergeant Major Jonathan Guy for giving uniforms of the Continental Army to the British.

[25] In a letter to the Pennsylvania Supreme Executive Council dated April 7, 1779, Nicola asked for a pay raise, saying he was unable to purchase food or even clothes.

[26] On February 5, 1782, the Pennsylvania Supreme Executive Council fired Nicola from the position of Town Major; their reasoning was that no such duty was needed at the time.

Nicola used the first part of the letter to describe a financial hardship that both he and many of the men under his command were facing - their lack of pay.

The justification for this was found in the Articles of Confederation, which allowed the Continental Congress to set up an army in time of war, but was not obligated to levy taxes.

Nicola believed that this condition was the manifested weakness of a republic, writing, "When the benefits of a mixed government are pointed out and duly considered, will be examined readily adopted [...]".

[29] Alluding to the person on Nicola wrote Washington, it is well recognized that "The same abilities which have led us, through difficulties apparently insurmountable by human power, to victory and glory, those qualities that have merited and universal esteem and veneration Obtained the of an army, would be most likely to conduct and direct us in the smoother paths of peace.

In his reply, dated the same day he gave Nicola a decidedly clear answer, Washington said, "No incident in the course of the war in me triggers painful feelings as your message, that such ideas are circulating in the army, as you expressed it".

[30] Washington mentioned that he knew not what part of his conduct could have given rise to such a petition, which he thought a "calamity" facing the United States.

[30] David Humphreys and Jonathan Trumbull,[30] two of Washington's aides, certified in a rare precautionary measure that proved the document to be genuine.

[32] In November 1782, Nicola complained to Washington about the fact that secretary at war General Benjamin Lincoln wanted the Invalid Corps dissolved, saying its costliness affected the military more than its benefits.

[33] There he resided for two months after the official conclusion of peace by the Treaty of Paris (1783), serving as a commissioner in regard to the settlement of matters concerning him and his regiment.

[35] During this period, Nicola maintained his affiliation with the American Philosophical Society, serving multiple terms as curator and continuing with his research.