He continued his education at Karlsruhe Polytechnic and then went to work for an engine manufacturer. Benz had a very specific motive for working at the engine plant— he dreamed of creating a horseless carriage, and he wanted to learn as much as he could about engines. After gathering what knowledge he could there, in 1871 he moved on to a position with a wagon and pump company in Mannheim, Germany, where he gained more valuable experience. By 1872, he was ready to open his own engine shop. Just before starting his business, he married Berta Ringer.

Benz was quite successful as a manufacturer, selling a large number of engines and winning the confidence of investors. With the financial backing of others, he founded the Mannheim Gas Engine Manufacturing Company, which he intended to use in part to develop his horseless carriage. Even though the venture quickly made a profit, Benz's investors did not want him to spend valuable resources on inventions. Benz unsuccessfully fought their decision and, after being in business for only three months, left the company. He quickly lined up new shareholders and founded a third business, Benz and Company, in October of 1883. The company was to sell stationary gas engines, but the new investors were also willing to support Benz's horseless carriage as long as it did not detract from the production of the primary product.

After two decades of planning his horseless carriage, Benz finally had the resources to make it a reality. In 1885, he debuted his automobile, a motorized tricycle that was revolutionary primarily for its use of a gasoline-powered internal combustion engine. Earlier in the century, self-propelled vehicles had been developed with steam engines, but the internal combustion engine marked an important breakthrough for automobiles. It provided a lighter, more compact, and more efficient means of powering a vehicle. It was the adoption of the internal combustion engine that made Benz's car a truly practical and appealing consumer product. For this reason, many consider Benz's 1885 motorized tricycle the first automobile.

Another important feature of Benz's vehicle was an electrical ignition system that used a battery to start the engine. This system became the basic model for all later ignitions. The tricycle also incorporated a carburetor, rack-and-pinion steering, a water cooling system, and rear springs. Benz held a public demonstration in the fall of 1885 to promote his invention, although he claimed to have first driven it the previous spring. On the road near his workshop, Benz and his wife began a ride on the automobile in front of a gathering of witnesses. After apparently forgetting to steer the tricycle, however, Benz quickly ran into a brick wall. Both passengers emerged from this early auto accident without injuries. The mishap did not dampen enthusiasm for Benz's creation—a positive review of the vehicle appeared the following summer in the publication Neue Badische Landeszeitung.

Benz continued to improve his design with the introduction of a second gear, a larger, 3-horsepower engine, and improved brakes and springs. The first sale of a Benz automobile occurred in 1887, after it had been displayed at the Paris Exhibition earlier in the year. At the Munich Imperial Exhibition in 1888, Benz was awarded a gold medal for his invention. This recognition brought in many orders for the automobile, which at that time was a novelty that was only affordable by the wealthy. Still, business was so good that the Benz Company grew to 50 workers by 1889 and soon moved to a larger factory where a new four-wheeled model began production in 1890.

Benz had given into the idea of a four-wheeled automobile reluctantly and only after much lobbying by others in his company who sought a more modern design. Unlike other automobile inventors, Benz did not feel that a car needed to physically resemble the traditional four-wheeled carriage. After the model of 1890, he was even more opposed to changes in his design. His opinions were so strong that after a major update of the Benz automobile in 1905, the manufacturer continued to drive his older models of the car.

One major challenger of Benz's claim to be the inventor of the automobile was a fellow German, Gottlieb Daimler. Daimler had created a better internal combustion engine and patented it five months before Benz's engine. The first vehicle in which he demonstrated his, however, was a bicycle, resulting in the first motorcycle. Those supporting Benz argued that the two-wheeled vehicle resembled the modern automobile less than the Benz tricycle. Regardless, Daimler also went on to become a successful producer of four-wheeled automobiles and became one of Benz's strongest competitors in both French and German markets. To try to gain a greater share of the French market, Daimler gave his car a French-sounding name— Mercedes—at the suggestion of a business partner. Despite their professional interest in each other, Benz and Daimler never met.

The Daimler company continued to do business after its founder died in 1900. Both it and the Benz company suffered a downturn during the economic depression after World War I. To strengthen their chances of survival, the companies merged to form Mercedes-Benz in 1926. By that time, Benz was no longer closely involved with the operation of the business, although he continued to receive recognition for his accomplishments as an automotive pioneer. His cars were collected by museums, and he was honored with a special procession of hundreds of automobiles from the city of Heidelberg to his home in Ladenburg in 1929. On that occasion, a number of prominent people made speeches in his honor and proclaimed him the inventor of the automobile. Two days later, on April 4, 1929, Benz died at his home in Ladenburg. Although later automotive innovators such as Henry Ford turned the car into a more successful product for the general public, Benz is remembered for his inventive genius and his groundbreaking work to create and market the first commercial automobile.

Nexon, John C., The Invention of the Automobile, Country Life, 1936.

Singer, Charles, A History of Technology, Volume 5: The Late Nineteenth Century, c. 1850 to c. 1900, Oxford University Press, 1958.