When did Eli Whitney make interchangable parts?

Eli Whitney developed the concept of interchangeable parts during the early 1800s, particularly while working on the production of muskets for the U.S. government between 1798 and 1809. His methods and innovations laid the groundwork for mass production and the assembly line, greatly influencing manufacturing processes. Whitney showcased his interchangeable parts system at a demonstration in 1801, which highlighted the efficiency and consistency of manufacturing.