Morse code was first presented to the public in 1836 by Samuel Morse when he transmitted the message, "What hath God wrought?" via wire from the city of Washington to Baltimore. He had been working on the electrical transmission of signals over wire since 1832. It was an unusual occupation for a man who had been trained as a painter and had successfully painted portraits for a living.
Morse developed and patented the device for sending messages. This device relied on the starting and stopping of an electric current. He needed a simple code and so developed the now famous Morse Code. The code uses short and long signals. The short signals are called "dits" and the long signals "dahs". A dit was assigned one time interval and a dah was assigned 3 time intervals. A certain combination of dits and dahs made up a letter. Between letters there was three time intervals and between words there were seven time intervals. These intervals acted in a manner similar to beats and measures in music. They could move faster or slower depending on the proficiency of the telegraph operator.
Morse code soon came into use all over the world. It easily translated to light signals (using lamps at night) and radio pulses once the radio was developed.
The code has actually been changed slightly from the one that Morse invented. There were originally five letters that had spaces, which sometimes created problems in translation from code to actual readable text. (C, O, R, Y and Z were the culprits.) Logically enough when Morse was developing his code, he wanted the most common letters to have the shortest code. To find out which letters were most common, he went to a printer and found counted how many of each various letter they kept in their trays. Being economical the printer would have more "e"s than say "j"s. You can see that "e" is a mere dit.