Final answer:
The first instance of American diplomacy was the alliance with France, solidified through the Treaty of Alliance after the American victory at Saratoga in 1777, which became complex during the French Revolution.
Step-by-step explanation:
The first piece of American diplomacy is generally considered the alliance with France during the American Revolution. After the American victory at Saratoga in 1777, the colonies secured an alliance with France in 1778 through the Treaty of Alliance. This alliance was paramount in the United States' battle for independence, as it provided crucial military support against Great Britain, particularly through the French navy. The relationship between France and the newly formed United States was initially strong. However, the onset of the French Revolution in the 1790s presented a significant diplomatic challenge for the US.
During the French Revolution, France sought to destroy all monarchies and began a war against Great Britain. The United States, then under George Washington's presidency, found itself in a precarious situation due to the earlier Treaty of Alliance. Regardless of differing opinions toward the French Revolution, Washington's advisers, including Secretary of State Thomas Jefferson and Secretary of Treasury Alexander Hamilton, recommended that the US should remain neutral to avoid jeopardizing American interests.
The ensuing events, including the controversial XYZ Affair, the perceived violations by France and Britain against American ships, and the intense debate within the United States itself, led to various diplomatic efforts. The most notable was the mission led by John Jay to London, which resulted in the Jay Treaty aimed at resolving several issues. During the subsequent Quasi-War with France from 1796 to 1800, President John Adams focused on building the US Navy to defend American interests. This period highlights the complexities of early American diplomacy and foreign policy decisions during the formative years of the nation.