As most Americans know, iconic Levi's blue jeans are no longer manufactured in the U.S.  However, there are a number of domestic blue jean companies that still manufacture clothes and pants in the U.S., including:

Buddy's Jeans feature cowboy cut denims, and are manufactured in New Hebron, Mississippi.

Diamond Gusset Jeans are proudly Made in USA, with a "Positively Tennessee" attitude.  The company also manufactures "Born and Worn in the USA" shirts.

Texas Jeans, which aims to make "rugged" and lasting blue jeans.