A timeline of United States inventions (1946–1991) encompasses the innovative advancements of the United States within a historical context, dating from the end of World War II to the end of the Cold War, which have been achieved by inventors who are either native-born or naturalized citizens of the United States. Patent protection secures a person's right to their first-to-invent claim of the original invention in question, highlighted in Article I, Section 8, Clause 8 of the United States Constitution which gives the following enumerated power to the United States Congress:

In 1641, the first patent in North America was issued to Samuel Winslow by the General Court of Massachusetts for a new method of making salt.James W. Cortada, "Rise of the knowledge worker, Volume 8 of Resources for the knowledge-based economy", Knowledge Reader Series, Butterworth-Heinemann, 1998, p. 141, , ."Manufactures of the United States in 1860; compiled from the original returns of the eighth census, under the direction of the Secretary of the interior", Publisher: Government Printing Office, Washington, 1865, p. cxcix: "Salt-making was commenced at Salein in 1636, and in 1641 Samuel Winslow was allowed, for 10 years, the exclusive right of making salt in Massachusetts by a new method." On April 10, 1790, President George Washington signed the Patent Act of 1790 (1 Stat. 109) into law which proclaimed that patents were to be authorized for "any useful art, manufacture, engine, machine, or device, or any improvement therein not before known or used." On July 31, 1790, Samuel Hopkins of Pittsford, Vermont became the first person in the United States to file and to be granted a patent for an improved method of "Making Pot and Pearl Ashes." The Patent Act of 1836 (Ch. 357, 5 Stat. 117) further clarified United States patent law to the extent of establishing a patent office where patent applications are filed, processed, and granted, contingent upon the language and scope of the claimant's invention, for a patent term of 14 years with an extension of up to an additional 7 years. However, the Uruguay Round Agreements Act of 1994 (URAA) changed the patent term in the United States to a total of 20 years, effective for patent applications filed on or after June 8, 1995, thus bringing United States patent law further into conformity with international patent law. The modern-day provisions of the law applied to inventions are laid out in Title 35 of the United States Code (Ch. 950, sec. 1, 66 Stat. 792).

From 1836 to 2011, the United States Patent and Trademark Office (USPTO) has granted a total of 7,861,317 patents relating to several well-known inventions appearing throughout the timeline below.

Post-war and the late Forties (1946–1949) 1946 Spoonplug A spoonplug is a form of fishing lure. The spoonplug was invented by Elwood L. "Buck" Perry, then a physics and math teacher in Hickory, North Carolina. Elwood Perry combined science with a logical approach to fishing to create a "total fishing system." He is credited as being the father of structure fishing and was later inducted into the National Freshwater Fishing Hall of Fame.

1946 Cancer chemotherapy Cancer chemotherapy can be traced directly to the discovery of nitrogen mustard, a chemical warfare agent, as an effective treatment for cancer. Two pharmacologists, Louis S. Goodman and Alfred Gilman were recruited by the United States Department of Defense to investigate potential therapeutic applications of chemical warfare agents. Autopsy observations of people exposed to mustard gas had revealed profound lymphoid and myeloid suppression. Goodman and Gilman reasoned that this agent could be used to treat lymphoma, since lymphoma is a tumor of lymphoid cells. They set up an animal model and established lymphomas in mice and demonstrated they could treat them with mustard agents. In collaboration with a thoracic surgeon, Gustav Linskog, they injected a related agent, mustine into a patient with non-Hodgkin's lymphoma. They observed a dramatic reduction in the patient's tumor masses. Although this effect lasted only a few weeks, this was the first step to the realization that cancer could be treated by pharmacological agents.

1946 DEET N,N-Diethyl-meta-toluamide, abbreviated DEET, is the most common active ingredient in insect repellents. It is intended to be applied to the skin or to clothing, and is primarily used to repel mosquitos. DEET was invented by the United States Army in 1946 following its experience of jungle warfare during World War II.

1946 Proton therapy Proton therapy utilizes a beam of protons to irradiate diseased tissue, most often in the treatment of cancer. The first suggestion that energetic protons could be an effective treatment method was made by Robert R. Wilson in a paper published in 1946 while he was involved in the design of the Harvard Cyclotron Laboratory (HCL). The first treatments were performed at particle accelerators built for physics research, notably Berkeley Radiation Laboratory in 1954 and at Uppsala in Sweden in 1957.

1946 Cloud seeding Cloud seeding, a form of weather modification, is the attempt to change the amount or type of precipitation that falls from clouds, by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation but hail and fog suppression are also widely practiced in airports. The method's use has ranged from increasing precipitation in areas experiencing drought to removing radioactive particles from clouds. Cloud seeding was invented by Vincent Schaefer in 1946.

1947 Transistor

In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. Because the controlled output power can be much larger than the controlling input power, the transistor provides amplification of a signal. The transistor is the fundamental building block of all modern electronic devices, and is used in radio, telephone, computer, and other electronic systems. From November 17, 1947, to December 23, 1947, John Bardeen and Walter Brattain at AT&T Bell Labs, underwent experimentations and finally observed that when two gold point contacts were applied to a crystal of germanium, a signal was produced whereby the output power was larger than the input. The American physicist and 1956 Nobel Prize winner, William Shockley, saw the potential in this and worked over the next few months greatly expanding the knowledge of semiconductors in order to construct the first point-contact transistor. Shockley is considered by many to be the "father" of the transistor. Hence, in recognition of his work, the transistor is widely, yet not universally acknowledged as the most important invention of the entire 20th century since it forms today's building blocks of processors found and used in almost every modern computing and electronics device.

1947 Defibrillator

Defibrillation is the definitive treatment for the life-threatening cardiac arrhythmias, ventricular fibrillation and ventricular tachycardia. Defibrillation consists of delivering a therapeutic dose of electrical energy to the affected heart. Dr. Claude Beck invented the defibrillator in 1947.

1947 Acrylic paint

Acrylic paint is fast-drying paint containing pigment suspended in an acrylic polymer emulsion. The first acrylic paint was invented by Leonard Bocour and Sam Golden in 1947 under the brand Magna paint.

1947 Correction fluid Correction fluid is an opaque, white fluid applied to paper to mask errors in text. It was very important when material was typed with a typewriter, but has become less so since the advent of the word processor. Correction fluid was invented by Bette Nesmith Graham in 1951 and originally called by the brand name Mistake Out.

1947 Mobile phone

A mobile phone, or cell phone, is a long-range, electronic device used for mobile voice or data communication over a network of specialized base stations known as cell sites. Early mobile FM radio telephones were in use for many years, but since the number of radio frequencies were very limited in any area, the number of phone calls were also very limited. To solve this problem, there could be many small areas called cells which share the same frequencies. When users moved from one area to another while calling, the call would have to be switched over automatically without losing the call. In this system, a small number of radio frequencies could accommodate a huge number of calls. The first mobile telephone call was made from a car in St. Louis, Missouri on June 17, 1946, but the system was impractical from what is considered a portable handset today. The equipment weighed 80 lbs, and the AT&T service, basically a massive party line, cost $30 per month plus 30 to 40 cents per local call. The basic network of hexagonal cells were devised by Douglas H. Ring and W. Rae Young at AT&T Bell Labs in 1947. Known as the "father of the cell phone," Martin Cooper invented the first handheld cellular/mobile phone in 1973.

1947 Instant camera

The instant camera is a type of camera with self-developing film. In 1947, Edwin H. Land invented a new camera that produced photographic images in 60 seconds. A colored photograph model would follow in the 1960s and eventually receive more than 500 patents for Land's innovations in light and plastic technologies.

1947 Supersonic aircraft

In aerodynamics, the sound barrier usually refers to the point at which an aircraft moves from transonic to supersonic speed. On October 14, 1947, just under a month after the United States Air Force had been created as a separate service, tests culminated in the first manned supersonic flight where the sound barrier was broken, piloted by Air Force Captain Chuck Yeager in the Bell X-1.

1948 Hair spray

Hair spray is a beauty aqueous solution that is used to keep hair stiff or in a certain style. Weaker than hair gel, hair wax, or glue, it is sprayed to hold styles for a long period. Using a pump or aerosol spray nozzle, it sprays evenly over the hair. Hair spray was first invented and manufactured in 1948 by Chase Products Company, based in Broadview, Illinois.

1948 Windsurfing

Windsurfing, or sailboarding, is a surface water sport using a windsurf board, also commonly called a sailboard, usually two to five meters long and powered by wind pushing a sail. In 1948, 20 year old Newman Darby first conceived of using a handheld sail and rig mounted on a universal joint, to control a small catamaran. Darby did not file for a patent for his design, however, he is regonized as the inventor of the first sailboard. However, what is clear from the historical record is that windsurfing, as it is known today, owes much if not all to the promotion and marketing activities of Hoyle and Diana Schweitzer. In 1968, they founded the company Windsurfing International in Southern California to manufacture, promote and license a windsurfer design. Together with Jim Drake, an aerospace engineer at the RAND Corporation, they were the holders of the very first windsurfing patent ever, which was granted by the United States Patent and Trademark Office in 1970, after being filed in 1968.

1948 Cat litter

Cat litter is one of any of a number of materials used in litter boxes to absorb moisture from cat feces and urine, which reduces foul odors such as ammonia and renders them more tolerable within the home. The first commercially available cat litter was Kitty Litter, available in 1948 and invented by Ed Lowe.

1948 Video game