Folding knives, also known as folders or pocket knives are the most popular of all the different types of knives collected today. There was a time when every man and young boy for that matter carried a pocket knife. Within the folding knife category there are many special types and manufacturers. Most American collectors are interested mainly in knives mass produced for practical use in the United States.

One of the oldest knife manufacturers in the United States is John Russell who opened a factory on the Green River near Deerfield, MA in 1830. Among the most notable knives of American manufacture, in addition to John Russell, are several known as Case.

There were several because a whole family of Cases were making knives and they were rivals. The first Case firm was known as Case Brothers Cutlery Company, which was founded in 1896 in Little Valley, NY by the three younger sons of Job Case. John, Jean and Andrew made their "Tested XX" knife famous. However, they were later overwhelmed by Russell Case, a son of their oldest brother, who worked for John, Jean and Andrew as a salesman. Russell quit after an argument over money and started a company named after his father, W.R. Case and Son. Vintage knives made by any of the Cases are very sought-after.

Collectors of American folding knives also look for knives made by the Winchester and Remington gun companies. They started making knives after WW1. Other popular brands include Buck, Camillus, Colonial, Ka-Bar and Schrade. Novelty knives and advertising knives were very popular in the 1920s and 1930s. Many large companies such as Coca Cola gave away many advertising knives made by some of the companies mentioned above.

Collecting vintage folding knives can be a fun, educational, rewarding and sometimes a profitable hobby. The best place to buy or sell vintage knives is eBay.