The international telephone service between Spain and the United States was officially inaugurated on October 13, 1928. The ceremony was presided over by King Alfonso XIII of Spain and Calvin Coolidge, President of the United States, who took part in the inauguration ceremony from the cities of Madrid and Washington, respectively. Both heads of state took advantage of the occasion to exchange some cordial and warm words of greeting in the name of the Spanish and American people The beginning of this telephone service connection with the United States was considered to be the most important technological milestone achieved in the history of Spanish telecommunications until that date This communications link was possible thanks to a complex telephone circuit covering a distance of just over eight thousand kilometers in each direction. It linked both countries via France, the English Channel, England, Scotland, and the Atlantic Ocean, using all the transmission media known at that time: open-wire lines, underground cables, submarine cables and radio or wireless communication.