Schematic plan · American Civil War

Battle of Gaines's Mill

27 June 1862
Virginia
Victory for USA

All battles The event in the chronicle Wikipedia

A schematic plan, generated from the statistics of the CAA Database of Battles: the armies' size and width, the hours of fighting, the plan of attack and the outcome are as recorded; the ground and the positions are not.

Confederacy (Cs Army of Northern Virginia, 57,018 men under Lee) attacked USA (US Army of the Potomac, 34,214 men under Porter) in Virginia. The CAA Database of Battles records 8 hours of fighting on a front of 3.6 km, a frontal attack against hasty defense, and that USA held. Losses: Confederacy 8,751 (15%), USA 6,837 (20%).

This plan is generated from those figures. It shows the shape of the battle the database describes: the size and width of the armies, the plan of attack and the outcome. It does not show where the units actually stood.

The armies

Confederacy

Lee

Unit	Arm	Men
Confederacy left wing	Infantry	13,684
Confederacy centre	Infantry	18,246
Confederacy right wing	Infantry	13,684
Confederacy reserve	Infantry	11,404
Lee	Commander	—
In this plan		57,018

USA

Porter

Unit	Arm	Men
USA left wing	Infantry	8,211
USA centre	Infantry	10,948
USA right wing	Infantry	8,211
USA reserve	Infantry	6,843
Porter	Commander	—
In this plan		34,213

What the sources report

	Confederacy	USA
Strength, this plan	57,018	34,214
Losses, this plan	8,751	6,837

In the CAA Database of Battles

CDB90 no. 185, “Gaines'S Mill”, compiled for the US Army to study what decides battles. These are the figures a what-if engine can be calibrated against.

Fighting: 8 hours
Winner: the defender
Terrain: Rolling, Mixed
Weather: Dry, Sunny, Temperate, Summer, Temperate
Defender’s posture: Hasty defense
Front width: 3.6 km (attacker), 3.6 km (defender)

Force	Strength	Losses	Horse	Guns	Plan and outcome
Confederacyattacker	57,018	8,751	—	—	Frontal attack; Repulse
USAdefender	34,214	6,837	—	—	Defensive plan

Attacker’s advantages initiative +1

CDB90 (US Army Concepts Analysis Agency, 1990), tidy edition by Jeffrey B. Arnold; data under ODC-BY 1.0.

Notes

On this reconstruction

Generated automatically from the statistics in CDB90. Frontages, depths, distances, the order of events and the terrain are schematic: they follow the recorded strengths, front widths, hours of fighting, tactical plan and outcome, not maps or accounts of the battle. The sources give no hours; the timing is conjectural.

Sources

US Army Concepts Analysis Agency; tidy edition by Jeffrey B. Arnold, CAA Database of Battles (CDB90), no. 185 · ODC-BY-1.0Strengths, losses, front widths, hours of fighting, tactics and outcome.
Wikipedia contributors, Battle of Gaines's Mill · CC-BY-SA-4.0

Facts gathered from Wikidata (CC0), Wikipedia (CC BY-SA 4.0) and Wikimedia Commons (licence per file); the plan and its text are timeastra’s own.