Alexander Graham Bell (1847–1922) was the Scottish-born inventor of telephone. Graham immigrated to Canada with his parents in 1870. He moved to Boston, where he began studying speech and experimenting in sound. There, he opened a school to train teachers of the deaf and became a professor at Boston University. In 1874, Bell began to envision a device that would allow speech to be transmitted electronically. On March 7, 1876, he received a patent for the telephone. In June of that year, he demonstrated the new device at the Philadelphia Centennial Exposition. The Bell Telephone Company was soon organized. Other inventors and companies tried to claim Bell’s invention, but he successfully defended against their attempts. Bell spent his later years on a number of scientific pursuits and technical innovations, though he is best remembered as the inventor of the telephone.