ACW
1862
Civil War campaign rules for the Eastern Theater,this is the home grown rule set that is used in the Civil war. 
A Hotter Fire
A simple set of ACW ironclad rules usable at 1/1200th and 1/600th.
A Perfect Sheet of Flame
This is the latest version of the "A Perfect Sheet of Flame" rules system, which has replaced the "Iron Brigade" rules system. These rules are regimental level rules, with a scale of 1:20 figures = actual men and 1 inch = 25 yards real world distance.
ACW-DBA
A conversion for the American Civil War in DBA by Craig Cartmell.
ACWarmaster
These trial rules and army list variants allow players to recreate large American Civil War battles using Games Workshop’s Warmaster rules.
ACW Sh*t For Real Men
A set of command and combat orientated 15mm dynamic grand tactical rules, which the author has been writing for a few years. An earlier version was published in Broadsword Magazine in Australia in 2005. They are (now very remotely) based on AH's Napoleons Battles, Paddy Griffith et al. Some army lists.
American Civil War
Rules for 25/28mm figures, where 1 figure represents 25 men.
American Civil War Naval Rules
These rules were originally produced to only cover both sides of an A4 page., using simultaneous movement.
American Civil War Riverine Actions
The simple rules given here, that I designed for ACW riverine actions can be taken as an example of how you might go about quickly getting down to the bare essentials of a playable game. In fact these are so basic that I've christened them 'Noddy'.
American Civil War Rules
These rules are designed to be used with 15mm. figures. They are written by: Paul Rogers.
Battle of Gettysburg
Fast and Easy Rules for the Battle of Gettysburg (1863).
Billy Yank
10mm rules taking the best of a number of free online rules and meshed together and it seems to have turned out rather nicely.
Bucket o Muzzleblast
This is a basic set of rules for battles from the Revolutionary War era up to the Civil War era. It is intended for soldiers as small as 15mm and as tall as 30mm.
Chaos of Battle
Overall goal is to provide 15mm miniatures gameplay that models higher level command and maneuver up to and following battles some lasting several days.
Civil War in Thirty Minutes
A Fast Simulation of the Battle in the East in 1862.
Cold Harbour
A simple working set of land based rules used by the author for many years.
Continuous Fire Fight Rules
The mechanisms of play such as Infantry and Artillery fire, Movement, Close combat (Melee), and Morale are taken straight from Larry Brom’s rules with little if any change.
Crossing The Deadly Ground
An update of the Continuous Fire Fight Rules.
Damn The Torpedoes
Fast play rules for The Battle of Mobile Bay. An ironclad game.
Days of Glory
Days of Glory is a set of rules for wargaming in 15mm during the American Civil War.
De Bellis Americanus
A a set of ACW rules for DBA by Craig Cartmell.
Easy Civil War Rules
A simple set of rules by Don Lowry where a stand of figures represents 1,000 to 3,000 men.
Fields of Blue and Grey
A very different kind of American Civil War rules, that allow the grand sweep of corp level actions to be recreated while still using the regiment as the basic combat element. A simple set of rules, where command & control is as important as combat. Designed for 15mm figures or smaller, but usable with any scale.
G63 Gettysburg 1863
Hilarious boardgame that refights the battle of Gettysburg with 1 counter for each side.
Glory
Italian language rules.
Glory Days
These are a set of rules for fighting at regimental and brigade level. The smallest unit sizes are infantry and cavalry regiments, artillery batteries and General's Staff elements. Although developed with 20mm plastic figures in mind the ground scale lends itself equally well to 15mm metal.
Hair Roller Armies American Civil War
Polish language rules for the ACW period.
Hardtack
American Civil War variant of Stargrunt II.
Hell In Miniature
These rules try to place the player in the role of Divisional or Corp commander, generally saddled with a bunch of troublesome, inept and downright worthless subordinates whose sole aim in life is to frustrate your well deserved victory.
Hex Command: Gunpowder
Boardgame ease and the beauty of miniatures, but keeping the flavour of historical command. ACW/Gunpowder rules.
Honor and Glory
These rules create a strategic game that primarily depends upon overall command and control of troops and their morale and not the actions of individual figures.
Iron Brigade
Tactical ACW rules. Each unit represents a regiment of infantry or cavalry or a battery of artillery.
Ironclad Gunboat
A set of rules for the ACW naval. An adaptation of a set by Lowry and Wham.
Ironclads
Conversion of the Games Workshop game Man'o'war for American Civil War Ironclads.
Jack Scruby's Basic War Game Rules
These can be used for any Musket Period war game merely be extending or shortening the range of musket and artillery fire. Thus for Civil War you would extend the range for Napoleonic you would shorten it. For use with N gauge figures.
Large Scale ACW Rules
Written for play large games where 1 unit is 1 division includes sample order of battle for Gettysburg.
Larry Reeves' "Regimental" rules
As used in the game: Assault on the Stockade Redan.
North Against South
These rules are based on the hybrid miniature/boardgame "Battle Cry" designed by Richard Borg. Their sole purpose is to convert the game into a proper tabletop miniature wargame.
North and South
This is a card driven wargame. It is inspired by the Battle Cry game by Richard Borg. In order to play the game, you need a copy of the Battle Cry game for the cards and the dice that come with it.
Regimental Fire and Fury
Americas Wars 1775 - 1865. Charts here.
Regimental Fury 2.8
A grand tactical regimental level rules supplement for Fire and Fury.
Regimental on to Richmond
Regimental on to Richmond by Tom Barkalow, is a set of miniature rules covering tactical actions in the American Civil War. 1 inch = 25 yards, 1 turn = 10 to 15 minutes, and 1 figure = 20 to 25 men. The mounting system is compatible with other popular sets such as Fire & Fury & Johnny Reb.
Rules for ACW River and Coastal Naval Actions 1861-1865
These rules have been developed to allow players to recreate the Naval actions of the American Civil War. The term Naval is used advisedly as many actions took place in rivers and estuaries, and, in many cases, less than six feet of water. Designed for 1:600 scale ships.
Seeing The Elephant
These rules are designed primarily for smaller actions of the ACW, but can be used for larger actions such as Gettysburg, etc. by adjusting the ground scale and figure scale.
SHAM (Steve's Horse and Musket Rules)
Simple Horse, Foot and Musket rules that can be used for ACW, 19th Century Periods.
Simple ACW Rules
Eric Woods' one-page (front and back) rules for ACW games. From a former Jackson Gamer.
Smoke On The Water
Smoke on the Water are Canis Publishing's wargames rules for naval actions from the American Civil War. Designed for use with either 1/600th or 1/1200th scale miniatures, they are intended to give a good feel for the period without sacrificing playability.
Southern Fury
A fun, simple miniatures game that can be played with fifty figures or five hundred figures in about two hours. The rules are geared toward simplicity and ease of play over detail. Join the Yahoo group.
The American Civil War Rules
These are fairly simple rules which require only tape measures and six-sided dice. The simplicity is good if you're playing the game with your children or if you just don't like complications. The board is set up to 25mm (1/72) scale.
The Revised Brom American Civil War Rules
25mm ACW ruleset. This is based on the BROM ruleset, this set has the best parts of several different sets and makes a much more realistic simulation.
There Stands Jackson
Fast play rules for Battle of First Bull Run (1861).
Two Flags One Nation
Figure rules for small tables or using cardboard units on paper maps.
We are the Flank - The Big Fight for Little Round Top
Fast and Easy Rules for Replaying Part of the Battle of Gettysburg.