Search results for external-frame-backpacks are below:

https://pack-rabbit.com/

100% Made in the U.S.A., the patented Pack Rabbit™ and Pack Mule™ frame systems are ergonomically designed to improve posture and reduce physical strain when carrying heavy loads. They also incorporate an integrated low profile seat. -Pack Rabbit

◊ Note-> Not all of their products are manufactured in the USA.