Modern Organic Fabrics has gone out of business. You can check my Etsy shop: Modern Organic Fabrics for what remains of the inventory.
Below is a list of online shops that carry organic cotton and that I feel I can personally vouch for as having fabulous service:
Cloud9 Fabric:
My Happy Nursery:
Pink Chalk Fabrics
Fabricworm
Contemporary Cloth
Beyond The Sea:
Lola Pink Fabrics
Contemporary Cloth
Pink Chalk Fabrics
Ray-Stitch
Eden Fabrics
Nature Walk:
Hawthorne Threads
Fabricworm
Birch Fabrics:
Circa 50:
Fabricworm
Fabric Shoppe
Ray-Stitch
Eden Fabrics
Marine:
Fabricworm
Lola Pink Fabrics
Circa 60*Beach Mod
Fabricworm
Lola Pink Fabrics
Monaluna's Organic Fabrics:
Monaco:
Above All Fabric
Lola Pink Fabrics
Fabricworm
Monaluna
Eden Fabrics
Marin:
Monaluna
Fabricworm
Anika:
Monaluna
Fabricworm
DaisyJanie Fabrics:
Geo Grand:
Contemporary Cloth
Lola Pink Fabrics
The Cloth Seller
Marmalade Fabrics
Shades of Grey:
Contemporary Cloth
Tonic Living
Robert Kaufman Organic Fabrics:
Fabric Shoppe
Whipstitch
Pink Chalk Fabrics
Fabricworm
Marmalade Fabrics
Westfalenstoffe Organic Fabrics:
Bunte Fabrics
Volksfaden
Immertreu
The Cloth Seller
Good Luck Elphants:
Eden Fabrics
Harmony Art:
Stitch Simple
Near Sea Naturals
Contemporary Cloth
Eden Fabrics
Herbal Dyed Fabric:
The Cloth Seller
Eden Fabrics
Ray-Stitch
Handloom Shirting:
The Cloth Seller
Ray-Stitch
Bishopston Trading
Hemp and Hemp / Organic Blend Fabrics:
Eden Fabrics
Pickering Fabrics