Claude was born in Brűlon, France as the grandson of a French Baron. He was raised for church service, but lost his sinecure during the French Revolution. He and his four unemployed brothers decided to develop a practical system of semaphore relay stations, a task proposed in antiquity, yet never realized.
Claude's brother was Ignace Chappe (1760-1829). Ignace was a member of the Legislative Assembly during the French Revolution. With his help, the Assembly supported a proposal to build a relay line from Paris to Lille (fifteen stations, about 120 miles), to carry dispatches from the war.
The Chappe brothers determined by experiment that the angles of a rod were easier to see than the presence or absence of panels. Their final design had two arms connected by a cross-arm. Each arm had seven positions, and the cross-arm had four more permitting a 196-combination code. The arms were from three to thirty feet long, black, and counterweighted, moved by only two handles. Lamps mounted on the arms proved unsatisfactory for night use. The relay towers were placed from 10 to 20 miles (12 to 25 km) apart. Each tower had a telescope pointing both up and down the relay line.
In 1792, the first messages were successfully sent between Paris and Lille. In 1794 the semaphore line informed Parisians of the capture of Condé-sur-l'Escaut from the Austrians less than an hour after it occurred. Other lines were built, including a line from Paris to Toulon. The system was widely copied by other European states, and was used by Napoleon to coordinate his empire and army.
In 1805, Claude committed suicide by falling down a well at his hotel. He was said to be depressed by illness, and claims by rivals that he had plagiarized from military semaphore systems.
In 1824 Ignace attempted to increase interest in using the semaphore line for commercial messages, such as commodity prices, However, the business community resisted.
In 1846, the government of France committed to a new system of electric telegraph lines. Many contemporaries warned of the ease of sabotage and interruption of service because a wire was so easy to cut.
He died in Paris, France.