Some of the first telegraphs were made in the late 1700s, but these were hard to use because they had too many wires. Samuel Morse made a telegraph using only one wire. In 1844, he built a telegraph line from Baltimore to Washington, D.C., and soon, there were telegraphs all over the United States. This made it easier for people to talk to people far away and made it easier for people to move out West. A transatlantic telegraph cable and other developments linked the world by the end of the century. Radio telegraphy became widespread in the early 20th century, especially on ships.