 The " City of Spindles , " as Lowell came to be known , quickly became the center of the Industrial Revolution in America . New , large scale machinery , which had come to dominate the production of cloth by 1840 , was being rapidly developed in lockstep with the equally new ways of organizing workers for mass production . Together , these mutually reinforcing technological and social changes produced staggering increases : between 1840 and 1860 , the number of spindles in use went from 2 ¼ million to almost 5 ¼ million ; bales of cotton used from 300 @,@ 000 to nearly 1 million , and the number of workers from 72 @,@ 000 to nearly 122 @,@ 000 . This tremendous growth translated directly into large profits for the textile corporations : between 1846 and 1850 , for instance , the dividends of the Boston @-@ based investors , the group of textile companies that founded Lowell , averaged 14 percent per year . Most corporations recorded similarly high profits during this period . 
