On 5 August 1888, she was the first person to drive an internal-combustion-engined automobile over a long distance, field testing the Benz Patent-Motorwagen, inventing brake lining and solving several practical issues during the journey of 105 km (65 miles).

Bertha Benz was not allowed to study in the Grand Duchy of Baden, and her financial and practical engineering contributions have long been overlooked until the 21st century.

[2] On 27 June 1869, during an excursion by the Eintracht Club, she met and fell in love with machine lover and tinkerer Carl Benz, who was five years her senior and penniless, but had a head full of crazy ideas, and who could talk better about technology than about feelings.

[6] As an unmarried woman, she was able to do so; after she married Benz, according to German law, Bertha lost her legal power to act as an investor.

[11] Karl Benz was a poor marketer and faced competition by Gottlieb Daimler, which prompted his wife to undertake the test drive in 1888.

[6] On 5 August 1888, 39-year-old Bertha Benz drove from Mannheim to Pforzheim with her sons Richard and Eugen, thirteen and fifteen years old respectively, in a Model III, without telling her husband and without permission of the authorities, thus becoming the first person to drive an automobile a significant distance.

[1] Before this historic trip, motorized drives were merely very short trials, returning to the point of origin, made with assistance of mechanics.

[16] With no fuel tank and only a 4.5-litre supply of petrol in the carburetor, she had to find ligroin, the petroleum solvent needed for the car to run.

The wagon was three-wheeled, but the paths were driven by four-wheeled horse-drawn carriages, so the dainty front wheel rattled over tufts of grass, sticks and stones.

[8] The trip received a great deal of publicity, as she had sought, and was a key event in the technical development of the automobile.

She reported everything that had happened along the way and made important suggestions, such as the introduction of an additional gear for climbing hills and brake linings to improve brake-power.

[6] In 1925, Karl Benz wrote the following in his memoirs: "Only one person remained with me in the small ship of life when it seemed destined to sink.

"[19] In 1926, Benz & Cie. merged with Gottlieb Daimler and Wilhelm Maybach's company to form Daimler-Benz, which became home to the Mercedes-Benz.

Her fortunes had shrunk due to World War I and hyperinflation, but it did not seem to bother her, as she was accustomed to living modestly to the point of miserliness all her life.

She and her family were very quickly co-opted by Nazi propaganda, and as early as Easter 1933, a National Socialist memorial was inaugurated for Carl Benz in Mannheim, in which Bertha participated.

[24] The 2011 documentary The Car is Born, produced by Ulli Kampelmann, centered on the first road trip by Bertha Benz.

[2] In honor of International Women's Day in 2019, the modern Daimler company commissioned a four-minute advertisement dramatizing portions of Bertha Benz’ 1888 journey.