In the United States

• Production - 11,235 motor vehicles
• Some 88 new auto companies begin in 1903, 15 of them in Michigan
• Ford Motor Company is incorporated on June 16, 1903 with  $28,000 in capital. The company earns money immediately and pays a 10% dividend in November. Henry Ford is the company's vice president and chief engineer, with 25.5% interest; John S. Gray is president. Initial stockholders include John & Horace Dodge, Albert Strelow, Alex Y. Malcomson, and James Couzens
• Childe Harold Wills leaves the adding machine business to become Ford Motor Company’s first chief engineer and factory manager
• The Buick Company and Pierce-Arrow Company are formed
• The Association of Licensed Automobile Manufacturers (ALAM) is formed as the exclusive licensee of the Selden patent and includes the Electric Vehicle Company and 8 other companies. Until 1911, nearly all manufacturers of gasoline automobiles pay royalties through ALAM. Rejected as a ALAM licensee, Henry Ford is sued by George Selden for patent infringement. Selden claims to have invented the automobile, as currently produced, back in 1877. This launched an eight-year legal battle for Ford Motor Company in which James Couzens played a key role in developing legal strategy for Ford.
• Roy D. Chapin & Carl G. Fisher - sell the Automobile Equipment Company, maker of waterproof coverings and chain guards.
• B. A. Gramm - perfects the power take-off
• Dr. Horatio Nelson Jackson, an intrepid soul from Vermont and heir to the Payne's Celery Tonic fortune, made what many call the first transcontinental crossing in a motor car. The trip, in a two-cylinder, open-top Winton, consumed 65 days from San Francisco to New York. Dr. Jackson was accompanied on the trip by his faithful dog named Bud and an equally faithful mechanic named Sewall Cocker. The trio--including Bud--wore goggles throughout the traveling portions of the journey. At the conclusion of their Odyssey, the three were described as national heroes. A Packard and an Oldsmobile complete the crossing later that summer
• Woman drivers in New York City form their own auto club
• Oldsmobile advertises its cars in the Ladies Home Journal
• First auto industry forecast that the market saturation point has been reached
• Edith Wharton takes Henry James out for a spin in her Panhard; tells him she is working on another novel so that she can buy a better car
• World's Work, a popular magazine, notes: "Putting a motor car in order is child's play compared with getting a sick horse well."
• San Francisco merchants merchants build a safety island for passengers while waiting for a cable car
• William Phelps Eno publishes the first book on traffic engineering. New York police adopt his rules for traffic and create the first traffic bureau after the Times comments: "Only agile pedestrians can survive."
• New features: shock absorbers, windshields, mechanically operated intake valves (Olds and Rambler), compensating carburetors, sliding gear transmissions, square "bonnets", honeycomb radiators, Tonneau bodies (with rear seats), and T-head cylinder engines
• Bernr Eli ("Barney") Oldfield - Former bicycle racer, begins to achieve fame as driver of Henry Ford’s racer "999." His chief competitors are Mohawk, Packard, Peerless, and Winton.
• Tom Fetch drives a single cylinder Packard from San Francisco, starting June 20, to New York in 61 days.
• Motor - New industry publication.

US Auto Manufacturers

• Cadillac - a single cylinder, 7.3-horsepower Cadillac appears at the National Automobile Show; the first Cadillac automobile is completed and shipped
• Ford - July 23, Company sells its first car, a two-cylinder Model A, assembled at Mack Avenue Plant in Detroit
• Packard moves to Detroit, occupying the world's first factory made of reinforced concrete
• The Buick Company is formed, with funds advanced by Benjamin Briscoe, Jr, and Frank Briscoe, to build cars with a valve-in-head engine. The first Buick is tested.
• Jackson Automobile Company issues both a gasoline runabout and the Jaxon steamer
• Peerless adopts a pressed-steel frame; three others follow shortly
• power steering, operated by a separate electric motor is installed in a Columbus Electic Motor Truck
• J. D. Maxwell & Briscoe Brothers - Form Maxwell-Briscoe Company, to produce one of the most popular cars of the time
• Peerless - Adopts pressed steel frame construction
• Oldsmobile - Establishes world record at Daytona Beach by covering five miles in 6 1/2 minutes
• John & Horace Dodge - Become shareholders in Ford Motor Company in exchange for tooling their machine shop to build motors.
• Buick Motor Company - Founded and begins manufacture of cars with valve-in-head engines.
• Oldsmobile - Produces 4,000 "curved dash" Oldsmobiles
• Packard - Moves to Detroit, into the world’s first reinforced concrete factory building, designed by Albert Kahn

And From Around the World

• White Steamer - Makes perfect score in 650 mile reliability trial held by Automobile Club of great Britain and Ireland.
• England licenses drivers, including a six year old. No test required
• English motorists claim that a London-Birmingham motorway will ease suburbanization for workers
• British Parliament raises the speed limit from 12 to 20 miles per hour
• Express Motor Service Company of London rolls out the world's first gas-powered taxi: one among 11,400 horse-drawn cabs. By 1914 the number of horse-powered cabs on London's streets had dwindled to 1,400 and were outnumbered by automobile-powered cabs 5 to 1
• French authorities stop the Paris-Madrid race in Bordeaux after 10 are killed, including Marcel Renault, leading to a French ban on road races
• Mercedes introduces the gas pedal
• Tottenham England gets the first i.c. fire engine
• Vauxhall builds the first all-steel-bodied car
• F.I.A.T. (Fabbrica Itailana Automobili Torino) is formed in a takeover of Ceirano, a company founded in 1901 to make cars under Renault license using a De Dion engine