Lowell had been to England in 1811 or so, and it's an important part of the story that there's this transatlantic connection, because, of course, the Industrial Revolution had been going on in England for quite some time, prior to what we see as really the beginnings of industrialism in America. Lowell was amazed by what he saw there, and, in fact, did an act of industrial espionage. He sort of memorized what this machine technology looked like, particularly the power loom, which was essential to mass production of textiles. And he came back to the States, helped create a blueprint, and, with the sort of secrets to the power loom unlocked, was ready to go into business.
They established, Lowell and his associates, the first fully integrated textile factory, the centralization of production under one roof, all the steps of the manufacturing process from raw cotton to the final product of finished cloth -- what economists call vertical integration within one site. And this was in part the genius, if you will, of the manufacturing mills at Lowell. It was totally different than the way in which textiles had been produced earlier, from spinning yarn to weaving cloth worked on in the home, outwork, piecework, a lot of the work being done by women in the home, only for home consumption, not for production for market. Here you have massive production on a scale, the creation of a market economy. So this isn't just for home use; this isn't just for local transactions. This is production for market for export, for investment.
Key to this work was the recruitment of labor. And ideally, these investors -- And by the way, they were very successful. Historians have calculated that their investments in manufacturing returned 20 to 30 percent profits for them every year. I mean, these guys were not just in it for benevolence or in it because they thought America needed to be a manufacturing, industrial power. They were making a lot of money out of Lowell, and so the cheaper the labor the better. And what they found was an available population of women -- young girls, more than 40,000 of them, who could come to these mills, who wanted to come to these mills for a variety of reasons that are worth examining, and work, apply their labor. In all, a total of some 32 mills controlled by 10 major firms, carrying different names -- Merrimack, the Middlesex, the Hamilton -- had a total value of over $10 million in 1840.
These girls, these laborers, are at the heart of the story of Lowell. Without them we have no story. Who were they? Where did they come from? Why did they come? I don't have the answers to all those questions. And some of those questions we need to sort of recover from reading the sources that are available to us that explain their motives, their experiences, and their desires. But we know that their ages tended to range from 16 to about 30 and that their stay averaged about four years in the mills. They came from the middling ranks of society -- not the poorest classes, in terms of wealth; not the wealthiest.
The historian who's most exhaustively studied this, an historian named Thomas Dublin, who has written several books about Lowell and about the experience of farm to factory, has recovered all this information statistically by looking at the various payrolls, the various ledgers, all the kinds of surviving documents, so that he can piece together and trace the histories of the experience of these women at Lowell. He figured out, for example, that they tended to come from large families, those typically with more than seven children. Now, if you think about that, that might make sense. You come from a large family, there may be less of a need for you to do work on the farm or to fulfill your domestic obligations on the farm, thus freeing you, perhaps, to try the experience of going to the mills.
We also know that, once in the mills, kinship played an important role -- in other words, that there were extended kinship ties among the girls and among the women; family who talked to one another; those who heard of relatives working at one mill recruiting other relatives to come and work in another mill. We know that after these girls left the mills most of them married, but because of their experience in the mills, they married at an older age, averaging around 29 years of age, which for the 1830s and 1840s is considerably older for marriage, which tended to occur a good 10 years or less before that.