Query

https://commons.wikimedia.org/wiki/File:Mina_Edison_1906.jpg

Thomas Edison proposed to his second wife, Mina, in Morse code.

“My later courtship was carried on by telegraph,” he wrote in his diary. “I taught the lady of my heart the Morse code, and when she could both send and receive we got along much better than we could have with spoken words by tapping out our remarks to one another on our hands. Presently I asked her thus, in Morse code, if she would marry me. The word ‘Yes’ is an easy one to send by telegraphic signals, and she sent it. If she had been obliged to speak of it, she might have found it harder.”