This period is especially problematic for basing. There are very rarely any *two* sets of AWI rules that agree on a basing scheme, so a common scheme across the period is really a pipe dream.
I personally settled on 1"x1/2" bases, and I now advise against it. It looks great when the troops are standing in two ranks and has the flexibility to also show open ranks, columns, skirmish lines, etc. Unfortunately, a 1/2" deep base with 2-3 figures on it is very tippy, and my AWI armies spend a lot of time falling on their faces or backs when crossing terrain or scaling hills.
In retrospect, I think 2 figures on 1"x3/4" bases is probably the most flexible. The extra bit of depth is just enough to make the bases *way* more stable, and also means figures advancing with leveled muskets can stand in the rear rank without having to carefully interleave the bayonets between the figures of the front rank. This is also the actual scheme recommended for Guns of Liberty, would work without modification for Regimental Fire & Fury, Warfare in the Age of Reason, Field of Battle, Loose Files & American Scramble, I *think* it should work without modification for British Grenadier (except maybe for the occasional single-figure stand for casualty marking), and could be adapted (by changing measurements or using sabots) to any system needing wider or deeper units. The units will look a bit lean and small in rules with fixed numbers of stands (e.g. Warfare in the Age of Reason, Field of Battle, etc.), but pretty cool if you double- or quadruple-base them on sabots into 8-12 figure two-rank stands.
My personal preference is to have "dense" infantry (i.e., those that can't use open or skirmish order) based 3/stand, and "loose" infantry based 2/stand. I like the look of tight shoulder-to-shoulder basing for troops standing in line, but troops that space out their stands for looser formations look funny in clumps of 3 with wide spaces between them. Unfortunately, this won't work for many of the bulkier 15mm lines, so for instance all of my Polly Oliver Hessians are mounted 2/base despite being the very *epitome* of "dense" infantry.
- Ix