When Americans hang their classic stars-and-stripes, some of their patriotic banners may have, in fact, been made by Annin & Co.

Founded in 1847, the family-run enterprise originally operated out of a small New York City loft, supplying signal flags for sailing ships. Today, the company produces more than 25,000 flags a week at its production plant just outside of Philadelphia.

Fifth-generation manufacturer Carter Beard explains that the current flag-making process is not much different from what it was 50 to 80 years ago. The red and white stripes and the star-filled blue field (called the canton) are all joined together by a series of sewing machines. 

One element that has changed over the decades, however, is the material: the first flags were made from cotton, but nowadays, more durable fabrics such as nylon and polyester are used.

Although a flag can remain in good shape for about 30 years, some wear out long beforehand because the end of the flag can destroy itself when it waves fiercely in strong wind. For that reason, each Annin & Co. flag has a fly hem -- a protective stitch that guards against excess wear and tear.