Where can i get information on a quilt that was my grandmothers?

ILGWU is the International Ladies' Garment Workers' Union. It's a huge organization and about the only thing that tag will tell you is that the quilt was embled in the US and which union local represented the emblers. There's probably not much intrinsic value to the quilt, though if it's in a decent condition and is hand-pieced you might get $150 for it at a good consignment or antiques shop.