Where were most of North Carolina's textile mills located in the early 1900s?

Philadelphia

Explanation:

Most of North Carolina's textile mills were located in Philadelphia in the early 1900s and this was due the availability of cheap labor and readily available raw materials for the production of textiles.

North Carolina was famous in the early 1900s for its massive production of textiles in America. as at 1921 North Carolina textile mills produced $191 million worth of textiles in America and that was more than double of what is produced in 1914, this showed that the textile industry in North Carolina was flourishing very well.