Samuel Finley Breeze Morse’s first passion was not science or electricity – it was painting. He was in Washington, in the middle of one of his commissions when a messenger brought the news that his wife back home in Connecticut several days before had fallen gravely ill. She died before Morse got back, and in his grief he focused his attention on developing a faster means of communications over long distances.

On this day, January 6th, in 1838, Morse publicly debuted his telegraph machine, using electric currents transmitted by wire to manipulate a stylus attached to a magnet. Several years later the machine was modified to include dashes and dots representing the letters.

Although met initially with skepticism, the telegraph came to be in widespread use by the early decades  of the 20th century, particularly as a means for ship and airplane communication. Radio communication via telegraph was used to coordinate ship position and air strikes by the navies of both Allies and Axis in World War II.