Wireless Telegraphy was invented when?

Marconi made transmission over practical distances possible.

As far back as Faraday and Hertz in the early 1800s, when it was discovered that radio waves could be used to send telegraph messages. In 1832, James Bowman Lindsay gave a classroom demonstration of UHF wireless telegraphy to his students. By 1854 he was able to demonstrate transmission across the Firth of Tay from Dundee to Woodhaven (now part of Newport-on-Tay), a distance of two miles. Various wireless telegraphy devices started appearing in the 1860s. Heinrich Hertz demonstrated the existence of electromagnetic radiation (radio waves) in a series of experiments in Germany during the 1880s.

In St. Louis, Missouri, Nikola Tesla made the first public demonstration of a modern wireless system in 1893. Addressing the Franklin Institute in Philadelphia and the National Electric Light Association, he described and demonstrated in detail the principles of wireless telegraphy and radio. The apparatus that he used contained all the elements that were incorporated into radio systems before the development of the vacuum tube. This led to work in using radio signals for wireless communication, initially with limited success. Using spark-gap transmitters plus coherer-receivers were tried by many experimenters, but several were unable to achieve transmission ranges of more than a few hundred metres. This was not the case for all researchers in the field of the wireless arts, though. By 1897, Guglielmo Marconi conducted a series of demonstrations with an economical radio system for signalling for communications over practical distances. This helped popularize radio communication activity worldwide, which is covered in depth by Invention of Radio and History of Radio.

in the 1800's