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Laundry was first done in watercourses, letting the water carry away the materials which could cause stains and smells. Laundry is still done this way in some less industrialized areas and rural regions. Agitation helps remove the dirt, so the laundry is often rubbed, twisted, or slapped against flat rocks. Wooden bats or clubs could be used to help with beating the dirt out. These were often called washing beetles or bats and could be used by the waterside on a rock (a beetling-stone), on a block (battling-block), or on a board. They were once common across Europe and were also used by settlers in North America.
Various chemicals may be used to increase the solvent power of water, such as the compounds in soaproot or yucca-root used by Native American tribes. Soap, a compound made from lye (from wood-ash) and fat, is an ancient and very common laundry aid. However, modern washing machines typically use powdered or liquid laundry detergent in place of more traditional soap.
When no watercourses were available, laundry was done in water-tight vats or vessels. Sometimes large metal cauldrons were filled with fresh water and heated over a fire; boiling water was even more effective than cold in removing dirt. The washboard, a corrugated slab of a hard material such as metal, replaced rocks as a surface for loosening soil.
Once clean, the clothes were wrung out — twisted to remove most of the water. Then they were hung up on poles or clotheslines to air dry, or sometimes just spread out on clean grass.
The Industrial Revolution completely transformed laundry technology.
The mangle (wringer US) was developed in the 18th century — two long rollers in a frame and a crank to revolve them. A laundry-worker took sopping wet clothing and cranked it through the mangle, compressing the cloth and expelling the excess water. The mangle was much quicker than hand twisting. It was a variation on the box mangle used primarily for pressing and smoothing cloth.
Meanwhile 18th century inventors further mechanized the laundry process with various hand-operated washing machines. Most involved turning a handle to move paddles inside a tub. Then some early 20th century machines used an electrically powered agitator to replace tedious hand rubbing against a washboard. Many of these were simply a tub on legs, with a hand-operated mangle on top. Later the mangle too was electrically powered, then replaced by a perforated double tub, which spun out the excess water in a spin cycle.
Laundry drying was also mechanized, with clothes dryers. Dryers were also spinning perforated tubs, but they blew heated air rather than water.
In the United States and Canada in the late 19th and early 20th century, the occupation of laundry worker was heavily identified with Chinese Americans. Discrimination, lack of English-language skills, and lack of capital kept Chinese Americans out of most desirable careers. Around 1900, one in four ethnic Chinese men in the U.S. worked in a laundry, typically working 10 to 16 hours a day. 
New York City had an estimated 3,550 Chinese laundries at the beginning of the Great Depression of the 1930s. In 1933, with even this looking to many people like a relatively desirable business, the city's Board of Aldermen passed a law clearly intended to drive the Chinese out of the business. Among other things, it limited ownership of laundries to U.S. citizens. The Chinese Consolidated Benevolent Association tried fruitlessly to fend this off, resulting in the formation of the openly leftist Chinese Hand Laundry Alliance (CHLA), which successfully challenged this provision of the law, allowing Chinese laundry workers to preserve their livelihoods.
Washing machines and dryers are now fixtures in homes around the world.
In some parts of the world, including the USA, Canada, and Switzerland, apartment buildings and dormitories often have laundry rooms, where residents share washing machines and dryers. Usually the machines are set to run only when money is put in a coin slot.
In other parts of the world, apartment buildings with laundry rooms are uncommon, and each apartment may have its own washing machine. Those without a machine at home or the use of a laundry room must either wash their clothes by hand or visit a commercial laundromat.
[[File:|thumb|right|250px|Directions for hand-washing New Britain Standard Hygienic Underwear, circa 1915]] Although there may be communities in the United States that restrict or prohibit residents from using a clothesline, there are others that expressly prohibit passing legislation preventing the use of clotheslines. In Florida, a law states that "No deed restrictions, covenants, or similar binding agreements running with the land shall prohibit or have the effect of prohibiting solar collectors, clotheslines, or other energy devices based on renewable resources from being installed on buildings erected on the lots or parcels covered by the deed restrictions, covenants, or binding agreements". No other state has such explicit legislation. Vermont considered a "Right to Dry" bill in 1999, but it was defeated in the Senate Natural Resources & Energy Committee. The language has been included in a 2007 voluntary energy conservation bill, introduced by Senator Dick McCormack. Similar measures are being introduced in some parts of Canada, including the province of Ontario, as well.
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