The spinning jenny, invented in 1764 by James Hargreaves, was first used for large scale industry by Richard Arkwright.  The machine took over the work of many hand spinners thereby multiplying the yarn that could be spun by one laborer.  Once an industrialist provided the initial investment to buy the spinning jennies, to establish the mill, and to hire enough workers, huge profits were made.

More than any other device, the spinning jenny came to represent the social costs of the Industrial Revolution. The workforce at Arkwright's mill, which was probably typical, was mainly children from 7 to 13 years old who worked a thirteen-hour day crouched low beneath the machines.

With this advance, farmers improve cotton plantations to Level II. Ranchers improve Wool farms to Level II. Both will produce three units per turn when improved.