Hello,
Like the forum and the topic you have going here!
I wanted to share my websites in hopes that they might help people identify old USA pottery, with or without marks. The first one is -
Antique Pottery Identification Site contains information about the 24 most well know American potteries, a forum and other useful stuff.
My other site (which I took over from the previous owner of Frankoma Pottery) is about existing pottery manufacturers, collecting clubs, etc. This link will take you to a pottery marks section that I am in the process of completing.
Pottery Marks If you have a moment, please give me a visit!
Thanks,
Tyler
P.S. - If anyone can help me identify the green flower bowl at this page
http://www.oldantiquepottery.info/about.htm I would be really grateful!