Interchangeable parts speeded up production, made repairs easy, and allowed the use of lower-paid, less-skilled workers.
Eli Whitney invinted interchangable parts in 1789.
the catagory it would fall under would be household agriculture transportation and communication because they work for everything.
Not only did he create intergchangeable parts he also invinted the cotton gin!
Factorys & Cottages
Interchangeable Part where used in cottage and factorys starying in the 1790's
They are even used in todays factorys mechanic shops and anywere they are needed.