The last disco ball maker in the United States
Here are two articles about the last disco ball maker in the US, located in Louisville, KY. The company is named Omega National Products and at one point they made about 90% of the disco balls in all American venues. Today, of course, you can have a disco ball made elsewhere -- like China, for example -- for much cheaper and it's arguable (maybe questionable?) which one is of the better quality.