Norm Koger's Wargame Construction Set 3: Age of Rifles (AoR) is a turn-based wargame that covers battles and campaigns from the 1840s until 1905.  Originally published by SSI in 1996 this DOS-based game can now be downloaded for FREE.
Links to Historical Resources
The US-Mexican War 1846-48
Battle of Fredericksburg
The Crimean War Research Society
The American Civil War Homepage
The Egyptian Army, 1880-1900
AGE OF RIFLES
Buy the Osprey Campaign series from Amazon.co.uk
Buy the Osprey Essential Histories series from Amazon.com
Screenshots  

Click a thumbnail for a larger image.
Franco-Austrian War
American Civil War
Download this free game from C: DOS
Scenarios

AoR comes with a range of ready-made campaigns and scenarios.  The scenarios cover historic battles such as Alma, Antietam, Chickamauga, Gettysburg, Shiloh, Sedan, Isandhlwana and Omdurman.  There is also a scenario editor that gives you the freedom to design your own scenarios.  Many of these player-designed scenarios can be downloaded from the
Wargamer's Games Depot and the Yahoo! Age of Rifles Group.

I have designed several scenarios which cover battles from the Franco-Austrian War of 1859.  They can be found
here.

I have also created a scenario which depicts the Battle of Hastings in 1066.  The beta version of the scenario can be downloaded from
here.

The game's random scenario generator (
pictured here) can be used to generate random battles from most of the world's major conflicts between 1840 and 1905.  I have compiled a list of possible random battles on my Age of Rifles random scenarios page.
If you enjoy AoR you may like Dragoon, Fields of Strategy or Sid Meier's Gettysburg
My Favourite Games Homepage
Antietam on the Web
The 1862 Peninsula Campaign
.
Battle of Algiers
Dervishes
Zulu Dawn
The Russo-Japanese War Research Society
Boxer Uprising
Downloads

Age of Rifles (AoR) can be downloded for free from C:DOS Abandonware or the Home of the Underdogs.
Battlefield Anomalies
Windows XP

AoR is a DOS game - but it will work with Windows XP.  Many people can play AoR on a Windows XP machine without any problems - while others prefer to play the game with a DOS emulator called DOSBox.  This can be downloaded for free from the DOSBox website.

The best place to obtain technical support for AoR is the
Yahoo! Age of Rifles Group.
Historical Article Downloads
"The Art of War - Waterloo to Mons" by William McElwee (pdf file)
Online Manual

A copy of the game manual has been published on the Internet here.
The Franco-Prussian War Association
Mars-la-Tour 1870 (in French and German)
The Civil War Explorer
Duryee's Zouaves
The Battle of Spicheren 1870 (in French)
La Guerre de 1870-1871 en images (in French)
Selected Civil War Photographs
Photographic History of the Civil War. Pub 1912 (pdf files)
The Civil War Artillery Page
Civil War Battle Summaries by State
U.S. Civil War Generals
The Civil War Archive
Confederate Regimental History Links
Union Army Regimental History Index
The Longstreet Chronicles
The New Zealand Wars
Buffalo Soldiers & Indian Wars
Anglo Boer War Museum (Bloemfontein)
Rorke's Drift Victoria Cross Recipients
Gamedias:  Wargames News and Links.