When I was in 3rd or 4th grade and geography was still taught, I remember our textbook had a picture of Worcester in it. The caption under that picture said, "Worcester Massachusetts, the industrial capital of the world." It said Worcester's claim to fame was having more manufacturing per square mile than any other place on the planet. Worcester at the time had steel mills, shoe manufactures, plastics factories, envelope factories, textile mills, foundries, factories that made precision measure devices, a factory that made industrial scales, another that made textile looms. There were hundreds of small shops that made just about every type of small goods. There were three major baking companies, one of which made only pies. The largest employers that I remember were Norton Abrasives, Wyman Gordon, Heald Machine, Crompton and Knowles, Reed and Prince, Curtis and Marble, Washburn Steel and Wire, Brown Shoe, David Clark Co and Orbit Co both made products for the space program. Pullman standard built train cars, White and Bagley made Oilzum products which were high quality lubricants, Dapol plastics, Harrington Richardson made guns for WWII and Viet Nam. The repurposed mill buildings in Worcester and the ruins and scars of old manufacturing sites represent only a small percentage of the factories that once existed. Every three decker in Worcester was built as cheap housing for mill workers. There's still hundreds of those standing but thousands that disappeared as the city declined and tried to reshape it self. When 290 went in whole neighborhoods disappeared and Worcester has many empty back streets where mills once stood. Every large neighborhood in Worcester except the west side housed manufacturing. Very little remains. I prefaced your answer with all of this to give you an idea of the enormity of Worcester's industrial past which began in the 1800s. The boom time began during WWII and ended in the mid to late 70s. During that time Worcester had one of the fastest growing middle class in the country and what is no suburban was once rural. I want to add that all of the major manufacturers contributed billions in endowments to many of Worcester colleges and universities and large amounts to the Arts.