The ice trade, also known as the frozen water trade, was a 19th century industry, centring on the east coast of the United States and Norway, involving the large-scale harvesting, transport and sale of natural ice for domestic consumption and commercial purposes. Ice would be cut from the surface of ponds and streams, then stored in ice houses, before being sent on by ship, barge or railroad to its final destination around the world. Networks of ice wagons were typically used to finally distribute the product to domestic and smaller commercial customers. The ice trade revolutionised the U.S. meat, vegetable and fruit industries, enabled significant growth in the fishing industry, and encouraged the introduction of a range of new drinks and foods.

The trade was started by the New England businessman Frederick Tudor in 1806. Tudor shipped ice to the Caribbean island of Martinique, hoping to sell it to wealthy members of the European elite there, using an ice house he had built specially for the purpose. Over the coming years the trade widened to Cuba and the the American South, with other merchants joining Tudor in harvesting and shipping ice from New England. During the 1830s and 1840s the ice trade expanded further, with shipments reaching England, India, South America, China and Australia. Tudor made a fortune from the Indian trade, while brand names such as Wenham Ice became famous in London.

Ice is water frozen into the solid state. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions. The addition of other materials such as soil may further alter the appearance.

Ice appears in nature in forms of snowflakes, hail, icicles, glaciers, pack ice, and entire polar ice caps. It is an important component of the global climate, and plays an important role in the water cycle. Furthermore, ice has numerous cultural applications, from ice cooling of drinks to winter sports and the art of ice sculpting.

The molecules in solid ice may be arranged in different ways, called phases, depending on the temperature and pressure. Usually ice is the phase known as ice I_h, which is the most abundant of the varying solid phases on the Earth's surface. The most common phase transition to ice I_h occurs when liquid water is cooled below 0°C (273.15K, 32°F) at standard atmospheric pressure. It can also deposit from vapour with no intervening liquid phase, such as in the formation of frost.

Trade is the transfer of ownership of goods and services from one person or entity to another by getting something in exchange from the buyer. Trade is sometimes loosely called commerce or financial transaction or barter. A network that allows trade is called a market. The original form of trade was barter, the direct exchange of goods and services. Later one side of the barter were the metals, precious metals (poles, coins), bill, paper money. Modern traders instead generally negotiate through a medium of exchange, such as money. As a result, buying can be separated from selling, or earning. The invention of money (and later credit, paper money and non-physical money) greatly simplified and promoted trade. Trade between two traders is called bilateral trade, while trade between more than two traders is called multilateral trade.

Trade exists for man due to specialization and division of labor, most people concentrate on a small aspect of production, trading for other products. Trade exists between regions because different regions have a comparative advantage in the production of some tradable commodity, or because different regions' size allows for the benefits of mass production. As such, trade at market prices between locations benefits both locations.