The telephone was invented by Alexander Graham Bell, who is credited with being the first to patent and successfully demonstrate a working telephone device. Bell was granted the U.S. patent for an "Improvement in Telegraphy" (telephone) on March 7, 1876. On March 10, 1876, he made the first successful telephone call to his assistant, Thomas Watson. Although other inventors such as Antonio Meucci, Johann Reis, and Elisha Gray also contributed to the development of similar devices, Bell's patent and continued work made him known as the father of the telephone.