Pocket pistols

[Electric Miner]

Top: Classic Arms New Orleans Ace. Modern design boot pistol in .44 caliber.

Middle: Pedersoli Liegi Derringer modern design, based on any of a number of Belgian pocket pistols. .44 caliber

Bottom: Original pocket pistol, likely Belgian, might be U.S., from mid-1800's, .31 caliber.

[Marshal Will]

Lookin' good. You'd have to have a loose-fitting boot for any of those, though.

Here's one similar to yours on an auction site.

[Miguel Loco]

Great collection! I've always had a liking for those.

[Hawg]

Top: Classic Arms New Orleans Ace. Modern design boot pistol in .44 caliber.

Middle: Pedersoli Liegi Derringer modern design, based on any of a number of Belgian pocket pistols. .44 caliber

Bottom: Original pocket pistol, likely Belgian, might be U.S., from mid-1800's, .31 caliber.

I'd bet money it's not Belgian.

[Electric Miner]

With more research, I suspect you are right in it being American. I still would not guess it to be an Allen & Thurber, just based on quality issues.

[Hawg]

I found another one on a closed auction but it doesn't give a maker. It too is unmarked. http://www.antiquearmsinc.com/civil-war-boot-pistol.htm