ancient times: Camera obscuras used to form images on walls in darkened rooms; image formation via a pinhole
16th century: Brightness and clarity of camera obscuras improved by enlarging the hole inserting a telescope lens
17th century: Camera obscuras in frequent use by artists and made portable in the form of sedan chairs
1727: Professor J. Schulze mixes chalk, nitric acid, and silver in a flask; notices darkening on side of flask exposed to sunlight. Accidental creation of the first photo-sensitive compound.
1800: Thomas Wedgwood makes "sun pictures" by placing opaque objects on leather treated with silver nitrate; resulting images deteriorated rapidly, however, if displayed under light stronger than from candles.
1816: Nicéphore Niépce combines the camera obscura with photosensitive paper
1826: Niépce creates a permanent image
1834: Henry Fox Talbot creates permanent (negative) images using paper soaked in silver chloride and fixed with a salt solution. Talbot created positive images by contact printing onto another sheet of paper.
1837: Louis Daguerre creates images on silver-plated copper, coated with silver iodide and "developed" with warmed mercury; Daguerre is awarded a state pension by the French government in exchange for publication of methods and the rights by other French citizens to use the Daguerreotype process.
1841: Talbot patents his process under the name "calotype".
1851: Frederick Scott Archer, a sculptor in London, improves photographic resolution by spreading a mixture of collodion (nitrated cotton dissolved in ether and alcoohol) and chemicals on sheets of glass. Wet plate collodion photography was much cheaper than daguerreotypes, the negative/positive process permitted unlimited reproductions, and the process was published but not patented.
1853: Nadar (Felix Toumachon) opens his portrait studio in Paris
1854: Adolphe Disderi develops carte-de-visite photography in Paris, leading to worldwide boom in portrait studios for the next decade
The ruined abbey of San Galgano, between Rome and Florence
1855: Beginning of stereoscopic era
1855-57: Direct positive images on glass (ambrotypes) and metal (tintypes or ferrotypes) popular in the US.
1861: Scottish physicist James Clerk-Maxwell demonstrates a color photography system involving three black and white photographs, each taken through a red, green, or blue filter. The photos were turned into lantern slides and projected in registration with the same color filters. This is the "color separation" method.
1861-65: Mathew Brady and staff (mostly staff) covers the American Civil War, exposing 7000 negatives
1868: Ducas de Hauron publishes a book proposing a variety of methods for color photography.
1870: Center of period in which the US Congress sent photographers out to the West. The most famous images were taken by William Jackson and Tim O'Sullivan.
1871: Richard Leach Maddox, an English doctor, proposes the use of an emulsion of gelatin and silver bromide on a glass plate, the "dry plate" process.
1877: Eadweard Muybridge, born in England as Edward Muggridge, settles "do a horse's four hooves ever leave the ground at once" bet among rich San Franciscans by time-sequenced photography of Leland Stanford's horse.
1878: Dry plates being manufactured commercially.
1880: George Eastman, age 24, sets up Eastman Dry Plate Company in Rochester, New York. First half-tone photograph appears in a daily newspaper, the New York Graphic.
1888: First Kodak camera, containing a 20-foot roll of paper, enough for 100 2.5-inch diameter circular pictures.
1889: Improved Kodak camera with roll of film instead of paper
1890: Jacob Riis publishes How the Other Half Lives, images of tenament life in New york City
1900: Kodak Brownie box roll-film camera introduced.
1902: Alfred Stieglitz organizes "Photo Secessionist" show in New York City
1906: Availability of panchromatic black and white film and therefore high quality color separation color photography. J.P. Morgan finances Edward Curtis to document the traditional culture of the North American Indian.
1907: First commercial color film, the Autochrome plates, manufactured by Lumiere brothers in France
1909: Lewis Hine hired by US National Child Labor Committee to photograph children working mills.
1914: Oscar Barnack, employed by German microscope manufacturer Leitz, develops camera using the modern 24x36mm frame and sprocketed 35mm movie film.
1917: Nippon Kogaku K.K., which will eventually become Nikon, established in Tokyo.
1921: Man Ray begins making photograms ("rayographs") by placing objects on photographic paper and exposing the shadow cast by a distant light bulb; Eugegrave;ne Atget, aged 64, assigned to photograph the brothels of Paris
1924: Leitz markets a derivative of Barnack's camera commercially as the "Leica", the first high quality 35mm camera.
1925: André Kertész moves from his native Hungary to Paris, where he begins an 11-year project photographing street life
1928: Albert Renger-Patzsch publishes The World is Beautiful, close-ups emphasizing the form of natural and man-made objects; Rollei introduces the Rolleiflex twin-lens reflex producing a 6x6 cm image on rollfilm.; Karl Blossfeldt publishes Art Forms in Nature
1931: Development of strobe photography by Harold ("Doc") Edgerton at MIT
1932: Inception of Technicolor for movies, where three black and white negatives were made in the same camera under different filters; Ansel Adams, Imogen Cunningham, Willard Van Dyke, Edward Weston, et al, form Group f/64 dedicated to "straight photographic thought and production".; Henri Cartier-Bresson buys a Leica and begins a 60-year career photographing people; On March 14, George Eastman, aged 77, writes suicide note--"My work is done. Why wait?"--and shoots himself.
1933: Brassaï publishes Paris de nuit
1934: Fuji Photo Film founded. By 1938, Fuji is making cameras and lenses in addition to film.
1935: Farm Security Administration hires Roy Stryker to run a historical section. Stryker would hire Walker Evans, Dorothea Lange, Arthur Rothstein, et al. to photograph rural hardships over the next six years. Roman Vishniac begins his project of the soon-to-be-killed-by-their-neighbors Jews of Central and Eastern Europe.
1936: Development of Kodachrome, the first color multi-layered color film; development of Exakta, pioneering 35mm single-lens reflex (SLR) camera
World War II:

Development of multi-layer color negative films
Margaret Bourke-White, Robert Capa, Carl Mydans, and W. Eugene Smith cover the war for LIFE magazine

1947: Henri Cartier-Bresson, Robert Capa, and David Seymour start the photographer-owned Magnum picture agency
1948: Hasselblad in Sweden offers its first medium-format SLR for commercial sale; Pentax in Japan introduces the automatic diaphragm; Polaroid sells instant black and white film
1949: East German Zeiss develops the Contax S, first SLR with an unreversed image in a pentaprism viewfinder
1955: Edward Steichen curates Family of Man exhibit at New York's Museum of Modern Art
1959: Nikon F introduced.
1960: Garry Winogrand begins photographing women on the streets of New York City.
1963: First color instant film developed by Polaroid; Instamatic released by Kodak; first purpose-built underwater introduced, the Nikonos
1970: William Wegman begins photographing his Weimaraner, Man Ray.
1972: 110-format cameras introduced by Kodak with a 13x17mm frame
1973: C-41 color negative process introduced, replacing C-22
1975: Nicholas Nixon takes his first annual photograph of his wife and her sisters: "The Brown Sisters"; Steve Sasson at Kodak builds the first working CCD-based digital still camera
1976: First solo show of color photographs at the Museum of Modern Art, William Eggleston's Guide
1977: Cindy Sherman begins work on Untitled Film Stills, completed in 1980; Jan Groover begins exploring kitchen utensils
1978: Hiroshi Sugimoto begins work on seascapes.
1980: Elsa Dorfman begins making portraits with the 20x24" Polaroid.
1982: Sony demonstrates Mavica "still video" camera
1983: Kodak introduces disk camera, using an 8x11mm frame (the same as in the Minox spy camera)
1985: Minolta markets the world's first autofocus SLR system (called "Maxxum" in the US); In the American West by Richard Avedon
1988: Sally Mann begins publishing nude photos of her children
1987: The popular Canon EOS system introduced, with new all-electronic lens mount
1990: Adobe Photoshop released.
1991: Kodak DCS-100, first digital SLR, a modified Nikon F3
1992: Kodak introduces PhotoCD
1993: Founding of photo.net (this Web site), an early Internet online community; Sebastiao Salgado publishes Workers; Mary Ellen Mark publishes book documenting life in an Indian circus.
1995: Material World, by Peter Menzel published.
1997: Rob Silvers publishes Photomosaics
1999: Nikon D1 SLR, 2.74 megapixel for $6000, first ground-up DSLR design by a leading manufacturer.
2000: Camera phone introduced in Japan by Sharp/J-Phone
2001: Polaroid goes bankrupt
2003: Four-Thirds standard for compact digital SLRs introduced with the Olympus E-1; Canon Digital Rebel introduced for less than $1000
2004: Kodak ceases production of film cameras
2005: Canon EOS 5D, first consumer-priced full-frame digital SLR, with a 24x36mm CMOS sensor for $3000;