Historians generally submit operational art, and modern war for that matter, emerged during the industrial era wars of the nineteenth and early twentieth centuries when national conscription fielded massive armies of corps and divisions. This sustained campaigns of distributed maneuver across broad geographic theaters to achieve intermediate aims. Modern interpretations define operational art as the tactical employment of forces to achieve strategic objectives. Current operational theory concentrates less on large force groupings. Instead, it articulates the interaction between imagination and judgment that determine the intermediate ways to link tactics and strategy. No longer the purview of generals, American brigade and battalion commanders increasingly employ operational art. They execute campaigns with implications spanning all levels of war. Historical vignettes depicting field grade commanders using operational art are sparse. But the practice is not new to American military history. George Rogers Clark's Illinois campaign may provide an example where an eighteenth century field grade theater commander employed operational art using a small, independent force. Lieutenant Colonel George Rogers Clark led a bold campaign to reverse Britain's attempts to destroy Virginia's frontier settlements during the American Revolution. Between 1778 and 1779, he captured the Illinois region with just one hundred and seventy-five men, forced his adversary, Lieutenant Governor Henry Hamilton, into battle and defeated him in a surprise maneuver at Vincennes. This victory saved Kentucky and denied potential British-Indian penetrations east of the Appalachians might have altered critical events leading to Yorktown. This monograph analyzes how Clark linked the tactical employment of forces to achieve strategic objectives. It assesses whether Clark exhibited operational vision. It considers whether his campaign demonstrated the hallmark of operational art. And it evaluates Clark's operational flexibility through the techniques used to maintain the operational aim. The American Revolution in the West is inappropriately characterized as endless local skirmishes. Such depiction distorts the reality of Clark's operations. He continually balanced between offensive, defensive, and stability operations to achieve a strategic objective tied directly to the casus belli in the Declaration of Independence. As a result, the Illinois Campaign provides a narrative at the very roots of America's military heritage relevant to the future conflicts. One that demonstrates operational art is less about an era, formation, or technology and more about the scale, scope, and synchronization of action relative to the strategic aim. It is about achieving effectiveness in war.