United States From Wikipedia, the free encyclopedia

Water supply and sanitation
Main article: Water supply and sanitation in the United States
Issues that affect water supply in the United States include droughts in the West, water scarcity, pollution, a backlog of investment, concerns about the affordability of water for the poorest, and a rapidly retiring workforce. Increased variability and intensity of rainfall as a result of climate change is expected to produce both more severe droughts and flooding, with potentially serious consequences for water supply and for pollution from combined sewer overflows.^{[556][557][fn 7]}
Science and technology
Main article: Science and technology in the United States

Astronaut James Irwin walking on the Moon next to Apollo 15's landing module and lunar rover in 1971. The effort to reach the Moon was triggered by the Space Race.
The United States has been a leader in scientific research and technological innovation since the late 19th century. Methods for producing Interchangeable parts were developed by the U.S. War Department by the Federal Armories during the first half of the 19th century. This technology, along with the establishment of a machine tool industry, enabled the U.S. to have large scale manufacturing of sewing machines, bicycles and other items in the late 19th century and became known as theAmerican system of manufacturing. Factory electrification in the early 20th century and introduction of the assembly line and other labor saving techniques created the system called mass production.^[560]
In 1876, Alexander Graham Bell was awarded the first U.S. patent for the telephone. Thomas Edison's research laboratory, one of the first of its kind, developed the phonograph, the first long-lasting light bulb, and the first viable movie camera.^[561]The latter lead to emergence of the worldwide entertainment industry. In the early 20th century, the automobile companies ofRansom E. Olds and Henry Ford popularized the assembly line. The Wright brothers, in 1903, made the first sustained and controlled heavier-than-air powered flight.^[562]
The rise of Nazism in the 1930s led many European scientists, including Albert Einstein, Enrico Fermi, and John von Neumann, to immigrate to the United States.^[563] During World War II, the Manhattan Project developed nuclear weapons, ushering in the Atomic Age, while theSpace Race produced rapid advances in rocketry, materials science, and aeronautics.^[564][565]
The invention of the transistor in the 1950s, a key active component in practically all modern electronics, led to many technological developments and a significant expansion of the U.S. technology industry.^{[566][567][568]} This in turn led to the establishment of many new technology companies and regions around the county such as Silicon Valley in California. Advancements by American microprocessor companies such as Advanced Micro Devices (AMD), and Intel along with both computersoftware and hardware companies that include Adobe Systems, Apple Computer, IBM, GNU-Linux, Microsoft, and Sun Microsystems created and popularized thepersonal computer. The ARPANET was developed in the 1960s to meet Defense Department requirements, and became the first of a series of networks which evolved into the Internet.^[569]
These advancements then lead to greater personalization of technology for individual use.^[570] As of 2013, 83.8% of American households owned at least onecomputer, and 73.3% had high-speed Internet service.^[571] 91% of Americans also own a mobile phone as of May 2013.^[572] The United States ranks highly with regard to freedom of use of the internet.^[573]
In the 21st century, 64% of research and development funding comes from the private sector.^[574] The United States leads the world in scientific research papers andimpact factor.^[575]
Health