The Compromise of 1850 is introduced into Congress by Henry Clay as an omnibus bill designed to settle disputes arising from the conclusion of the Mexican War. It passes after Stephen Douglas divides the bill into several parts: California enters the Union as a free state; the slave trade (but not slavery) is abolished in Washington D.C.; the fugitive slave law is strengthened; and the Utah and New Mexico Territories are opened to slavery on the basis of popular sovereignty (allowing territorial voters to decide the issue without federa linterference).

"Bibless overalls" made of canvas are sold by the 20 year-old Levi Strauss in San Francisco. Within three years he will switch to denim and dye his pants indigo blue.

Millard Fillmore becomes the thirteenth president of the United States, when Zachary Taylor dies in office.

The US flag is modified to have thirty-one stars, reflecting the addition of one new state: California.

Arithmometer: first commercially successful mechanical calculator launched

The fast-acting Collodion process invented by Frederick Scott Archer. Images require only two or three seconds of light exposure. Collodion process, mostly synonymous with the "collodion wet plate process", requires the photographic material to be coated, sensitized, exposed and developed within the span of about fifteen minutes, necessitating a portable darkroom for use in the field. Collodion is normally used in its wet form, but can also be used in humid ("preserved") or dry form, at the cost of greatly increased exposure time. The latter made the dry form unsuitable for the usual portraiture work of most professional photographers of the 19th century. The use of the dry form was therefore mostly confined to landscape photography and other special applications where minutes-long exposure times were tolerable.

Isaac Singer patents the continuous-stitch sewing machine.

The Erie Railroad, now controlled by Daniel Drew, becomes the first rail line connecting the Great Lakes with New York City, and begins to compete with the Erie Canal as a transportation route.

In South Bend, Indiana, Clement and Henry Studebaker found Studebaker Brothers. Joined by a third brother, John, in 1858, the company will become the world's largest maker of wagons and carriages.

In Sweden, safety matches are patented by J. E. Lundstrom.

The brown paper bag is invented.

The elevator is invented, facilitating the future development of skyscrapers.

The U.S. state of Pennsylvania adopts a non-standard railroad gauge in order to prevent New York's Erie Railroad from establishing a route, through Pennsylvania, to Ohio.

The French Republic falls; Louis Napoleon (Napoleon III) is crowned Emperor.

The U.S. state of Massachusetts adopts a compulsory school-attendance law, the first effective example of such a law in the nation.

Potato chips are invented.

Commodore Matthew Perry sails into Japan's Edo Bay with his black ships (four modern, steam-powered warships), urging Japan to open trade policies with the United States.

Franklin Pierce becomes fourteenth president of the United States.

Kansas-Nebraska Act: In an attempt to spur population growth in the western territories in advance of a transcontinental railroad, Stephen Douglas introduces a bill to establish the territories of Kansas and Nebraska. In order to gain Southern support, the bill stipulates that slavery in the territories will be decided by popular sovereignty. Thus the Kansas-Nebraska Act repeals the Missouri Compromise ban on slavery north of 36 30' in the lands of the Louisiana Purchase.

Ostend Manifesto: The U.S. ministers to Britain, France, and Spain meet in Ostend, Belgium. They draft a policy recommendation to President Pierce, urging him to attempt again to purchase Cuba from Spain and, if Spain refuses, to take the island by force. When the secret proposal, called the Ostend Manifesto, is leaked to the press, it creates an uproar since Cuba would likely become another slave state.

On May 24, Virginia fugitive slave Anthony Burns is captured in Boston and returned to slavery under the provisions of the Fugitive Slave Act. Fifty thousand Boston residents watch his transport through the streets of the city in shackles. A Boston church raises $1500 to purchase his freedom and Burns returns to the city in 1855, a free man.

On May 30, the Kansas-Nebraska act is passed by Congress. The act repeals the Missouri Compromise and permits the admission of Kansas and Nebraska territories to the Union after their white male voters decide the fate of slavery in those territories.

Slavery is abolished in Peru and Venezuela.

The Republican Party is formed in the summer in opposition to the extension of slavery into the western territories.

André-Adolphe-Eugène Disdéri credited with introduction of the carte de visite (English: visiting card or calling card) format for portraiture. Disdéri uses a camera with multiple lenses that can photograph eight different poses on one large negative. After printing on albumen paper, the images are cut apart and glued to calling-card-size mounts. Photographs had previously served as calling cards, but Disdéri's invention of the paper carte de visite (i.e. "visiting card") enabled the mass production of photographs. On 27 November 1854 he patented the system of printing ten photographs on a single sheet (although there is no evidence that a system printing more than eight actually materialized). Disdéri's's cartes de visite were 6×9 cm, about the size of conventional (nonphotographic) visiting cards of the time, and were made by a camera with four lenses and a sliding plate holder; a design inspired by the stereoscopic cameras. The novelty quickly spread throughout the world. According to a German visitor, Disdéri's studio became "really the Temple of Photography - a place unique in its luxury and elegance. Daily he sells three to four thousand francs worth of portraits". The fact that these photos could be reproduced inexpensively and in great quantity brought about the decline of the daguerreotype and ushered in a carte de visite craze as they became enormously popular throughout Europe and the United States. Disdéri also invented the twin-lens reflex camera.

The Massachusetts Legislature outlaws racially segregated schools.

A mercury pump is developed by inventor Heinrich Geissler, to produce vacuum tubes. The first cathode rays will be observed in these tubes, after they are modified and improved by Sir William Crookes.

Engineer Frederick Taylor carries out "time-motion" studies of workers with the idea of making their labor more efficient. He will pioneer the "scientific management" of the workplace.

The Caning of Charles Sumner: Senator Charles Sumner delivers a stinging speech in the U.S. Senate, "The Crime against Kansas," in which he attacks slavery, the South, and singles out his Senate colleague, Andrew Butler of South Carolina, for criticism. In retaliation, Butler's nephew, Congressman Preston Brooks of South Carolina, attacks Sumner with a cane while the Massachusetts senator is seated at his desk on the floor of the Senate. The injuries he sustains cause Sumner to be absent from the Senate for four years. The episode revealed the polarization in America, as Sumner became a martyr in the North and Brooks a hero in the South. Northerners were outraged. Southerners sent Brooks hundreds of new canes in endorsement of his assault. One was inscribed "Hit him again." Brooks claimed that he had not intended to kill Sumner, or else he would have used a different weapon. In a speech to the House defending his actions, Brooks stated that he "meant no disrespect to the Senate of the United States" or the House by his attack on Sumner. He was tried in a District of Columbia court, convicted for assault, and fined $300 ($8,000 in today's dollars), but received no prison sentence.

A railway bridge spanning the Mississippi opens between Rockville, Illinois, and Davenport, Iowa. Abraham Lincoln, a lawyer, will defend the legality of the bridge before the Supreme Court, in response to a "right of way" suit brought by a steamship company.

During Easter vacation from London's Royal College of Chemistry, 18-year-old William Henry Perkin synthesized mauve, or aniline purple — the first synthetic dyestuff — from chemicals derived from coal tar. Mauve was enthusiastically adopted by the fashion industry in England and synthetic dyes quickly destroyed the market for natural substances derived from plants like indigo and madder. Perkin's creation was an accident — he was trying to synthesize quinine.

The "Bessemer process" for making inexpensive steel, which involves using blasts of cold air to decarbonize melted pig iron, is developed by inventor Henry Bessemer.

The 458-mile Wabash and Erie Canal opens after 24 years, and is the largest canal ever dug in the U.S. By 1860, however, sections will begin to be close, and, unable to compete for railroads, the entire Canal will be closed by 1874.

In South Africa, Boers establish the South African Republic (Transvaal), with Pretoria as its capital. Marthinus Wessels Pretorius, 37, is named the first president.

The Second Opium War (1856-1860) between Britain and China leads to further erosion of Chinese sovereignty.

Farmer Hinton Rowan Helper publishes The Impending Crisis of the South, and How to Meet It, in which he argues that slavery in economically unwise, and particularly devastating to small farmers who do not own slaves. He writes that slavery is "the root of all the shame, poverty, ignorance, tyranny and imbecility" in the South. He also argues that slavery foolishly ties up economic resources in human beings when it might be spent on labor-saving improvements.

The African slave trade is prohibited in the Ottoman Empire

The Dred Scott Decision makes the Missouri Compromise unconstitutional and increases tension between North and South over slavery in the United States. Writing for the majority, Chief Justice Roger B. Taney asserted that blacks were "beings of an inferior order, and altogether unfit to associate with the white race, either in social or political relations, and so far inferior that they had no rights which the white man was bound to respect." This embarrassing decision represents a low point in the history of the United States Supreme Court.

In Burrville, Connecticut, commercial production of Gail Borden's patented "condensed milk" begins. The product is made from skim milk, without any fat and without a number of nutrients found in cow's milk.

In California, Tokay, Zinfandel, and Shiraz grapes (all from Hungary) are first planted, and Italian honeybees are introduced. This is the beginning of the U.S. wine and honey industries. In North America, honey bees are an artificially introduced and invasive species.

Robert Wilhelm von Bunsen (along with Henry Roscoe) publish a design for a laboratory burner in Poggendorff's Annalen der Physik und Chemie, 100:84-85.

James Buchanan becomes fifteenth president of the United States.

Giuseppe Garibaldi, who returned to Italy in 1854 after several years working at Staten Island, New York, founds the Italian National Association. The organization is designed to promote the unification of Italy.

The US flag is modified to have thirty-two stars, reflecting the addition of one new state: Minnesota.

J. Schweppe & Co. Ltd. patents a quinine tonic water that they will begin selling in 1880.

John Landis Mason patents a reusable glass jar.

Abraham Lincoln, running for the United States Senate, declares "A house divided against itself cannot stand." He loses the race to Stephen Douglas, but his performance in there now-legendary debates leads to his nomination as the Republican candidate for president in 1860.

In Ireland, the group Sein Fein is founded.

The US flag is modified to have thirty-three stars, reflecting the addition of one new state: Oregon.

Harriet Wilson of Milford, New Hampshire, publishes Our Nig; or Sketches from the Life of a Free Black, the first novel by an African-American woman.

On October 16, John Brown leads 20 men, including five African-Americans, in an unsuccessful attempt to seize the Federal Armory at Harper's ferry, Virginia, with the goal of inspiring a slave insurrection. He was captured by US troops under the command of Colonel Robert E. Lee, tried, and hanged on December 2.

In Titusville, Pennsylvania, commercial production of petroleum begins, with drilling of the first well by Edwin Laurentine Drake. The well will produce approximately 400 gallons/day.

The first internal combustion engine is developed by Jean-Joseph-Etienne Lenoir. The engine uses coal gas.