Henry Knox was born in Boston, Massachusetts, on July 25, 1750. The first official U.S. secretary of war, Knox spent his entire professional life engaged in military affairs. From 1768 to 1776, he involved himself with military organizations based near his home in Boston, including three years of service with the Boston Grenadier Corps (1773-1776). A volunteer with the rebels at the outbreak of the Revolutionary War, Knox initially commanded the troops near Boston.

Following the colonists' successful defeat of their British foe in that area, he earned a formal promotion to captain in the Continental Army from General George Washington. By 1781, Knox was a brigadier general and was in charge of overseeing the production and supply of materiel for the colonial army.

Between 1782 and 1785, Knox took on additional responsibilities for the Army, becoming commander of the military post at West Point and performing the task of disbanding the American troops following the conclusion of the war. In 1785, Knox became secretary at war under the Articles of Confederation, serving until 1789. After the approval of the federal constitution and the inauguration of George Washington as the nation's first president, Knox entered Washington's cabinet as secretary of war, served from 1789 to 1794. Upon his retirement, he moved to an estate near Thomaston, Maine, and died there on October 21, 1806.