The Boston Associates was a term created by historian Vera Shlakmen in Economic History of a Factory Town, A Study of Chicopee, Massachusetts (1935) to describe a loosely linked group of investors. They included Nathan Appleton, Patrick Tracy Jackson, Abbott Lawrence, and Amos Lawrence, often related directly or through marriage, they were based in Boston, Massachusetts. By 1845, there were 31 textile companies—located in Massachusetts, New Hampshire, and southern Maine—produced one-fifth of all cotton and wool textiles in the United States. With the capital earned through these mills, they invested in railroads, especially the Boston and Lowell. These railroads helped transport the cotton from warehouses to factories. These Boston-based investors established banks—such as the Suffolk Bank—and invested in others. In time, they controlled 40% of banking capital in Boston, 40% of all insurance capital in Massachusetts, and 30% of Massachusetts' railroads. Tens of thousands of New Englanders received employment from these investors, working in any one of the hundreds of their mills.