I like the tactical aspect of the of the horse and musket period , which include FIW, AWI, War of 1812, Napoleonic and ACW.
I chose to exclude the Napoleonic and ACW because most the battles are large multi-divisional encounters, which makes fighting at 20:1 ratio problematic…so many figures. So, I chose the War of 1812 because most of the battles are divisional level and below. Plus it has so many interesting encounters and variables like gun boats, Indians, militia etc. Nonetheless, I think FIW and AWI would fit this requirement as well.
Once you have decided on the period then you need to decide on a set of rules.Even if you do not intend to game with others a good set of rules with give you a sound framework to build your armies.
I chose General de Brigade rules. Even though they are Napoleonic they are most suitable for the War of 1812. After all the War of 1812 was a subset of the Napoleonic wars.
Why General de Brigade?
General de Brigade (I have tried BP, Shako2 and others); it is a good balance between realistic rules that reflect Napoleonic tactics and quick play rules. It is scaled for 25mm and 15mm figure scales…inches for 25mm and cms for 15mm…throughout the rules for quick reference.
I like the 20:1 ratio, which forces one to consider the terrain vis a vis the formation the battalion is in. I also like the orders regime that forces one to think ahead and mitigates the 'sky general' aspect of most games. Units within a brigade must operate within the order constraints.
Most importantly I like the morale system that applies to units, brigades and divisions. This provides more realistic play so that units do not fight until the last man standing. The divisional size (there are corps optional rules if needed)is ideal for War of 1812 war gaming.
GdeB Deluxe has a page with suggestion rule adjustments for War of 1812 gaming. We have added our own addendum to reflect the realities of the War of 1812 battles.
Importantly, Gde B has an active forum to discuss the rules and their possible interpretations A great set of rules and highly recommended.
Lastly, the active blog is overseen by the rules author David Brown, which provides a venue for rules discussion for those seeking clarification. I find this blog most helpful.
If you decide on the AWI or FIW period, the G de B has set of rules for each period.
I hope this helps and good luck with your choice.