If you're talking about the American Made Brand (AMB) solid fabrics made by Clothworks Textiles, which IS a major fabric manufacturer, they are 78x74 threads, come in 50 colors, and are promoted as shirting weight with a soft yet firm hand. Compared to Kona Solids, a broadcloth with 60x60 threads, I would bet that the AMB would be much more like regular quality quilting cottons.

Unless Connecting Threads has changed their practices, their "USA made" fabrics are spun, woven and printed in Central and South America from USA grown cotton. Clothworks AMB line is grown, spun, woven, and dyed in the US, 100% made in America, from field to fabric.
http://americanmadebrand.com/about/

Me too, its nice to be able to buy American...

Bought a yard from American Made Brand and washed it and it is great. 100% american grown and made. and great choice of solid colors. I bought the color card and under $7.00 a yard. Yea
Also got 2 different yards of flower printed from Jo Anne's, washed and dried it and it is nice quality. I am so happy to have material made in America again. Will be ordering more solid color for a Dresden plate quilt. just haven't decided what solid color, will have to get out florals and see what color goes best with the colors I have.

I think connecting threads has said their fabric is not made or grown in the US.

Love the American made collection at Joanns.

Here's what connecting threads said on facebook a while back:

Ditto. I have ordered enough for a queen quilt and a wallhanging kit from Connecting Threads and everything was great.

I decided to start only using Hobbs batting as they use cotton grown in my Great State of Texas, supporting our local cotton farmers.

I just bought some from Joanne's but haven't had a chance to use it price was good and the fabric seemed good. I sure hope we bring home our factories and make things in our own country so we stay on top and have jobs for our men and women coming home and here already. USA first. Sue