In 1690, William Rittenhouse built a paper mill near Germantown, Pennsylvania, the only one in the New World until 1710. By 1775, there were only 20 paper mills in the colonies. As the population in America grew, so did the need for more paper.
Early on, papermakers realized that they needed to locate their mills near populated area that could provide a reliable supply of old rags, which were their main raw material. They also realized that they needed to be near a large supply of fresh water, both for turning the mill machinery and for washing the rag fibers.