Wilson's Creek: The West's First Fight, August 10, 1861 (1980)

Wilson's Creek is a grand tactical, regimental level simulation of the Civil War battle fought on 10 August 1861, five miles southwest of Springfield, Missouri. The game simulates the surprise Union attack (led by Brigadier General Nathaniel Lyon) upon an allied force of Confederate regulars led by Brigadier General Benjamin McCulloch, and Missouri State Guards led by Major General Sterling Price. The Battle of Wilson's Creek was one of the pivotal factors that kept Missouri in the Union.

The game consists of a 22"x34" map, 200 counters representing military units, leaders, and informational markers, rules booklets, dice, and (except for subscription editions) a box. Each Game-Turn represents 20 minutes of real time, and each hex covers about 125 yards from hexside to hexside. Each Strength Point is the equivalent of 100 men or 1 gun.

This is Volume 3 of the original SPI / TSR Great Battles of the American Civil War series.

(from the game's introduction and user's description)