In the 18th century, Americans burned a lot of wood to keep their homes warm. But everything from a log cabin to a brick house had an open fire place with a chimney made of brick or stone. These open fires were quite inefficient. As Adams notes, houses in the Northern states would burn ten to fifteen cords of wood per year (a cord being a pile of stacked wood 4x8x4 feet in size). The amount of effort that went into chopping down trees, sawing them in smaller pieces, and then splitting those pieces into firewood must have been immense. What Adams highlights however is the effort needed to ship and market firewood in the city. As forests near the large cities were depleted, firewood was shipped in from farther and farther away. Boston, Philadelphia, and New York had large regulated networks of cordwood suppliers. As firewood became harder to procure, Americans sought heating solutions.