International Marconi Day celebrates the accomplishments of radio pioneer Guglielmo Marconi on the Saturday closest to his birthday each year. Stations around the world activate a special operating event to celebrate.

On January 18, 1903, the first public two-way wireless communication occurred between the United States and Europe. A message from President Theodore Roosevelt was sent to King Edward VII from the South Wellfleet site. The site is preserved within the Cape Cod National Seashore in Massachusetts.

For International Marconi Day 2023, the Marconi Cape Cod Radio Club activated the site with their club call sign, KM1CC. Their event featured a special guest, the Director of the National Park Service Charles "Chuck" Sams III. The Director operated third party from the site for a scheduled QSO with W1AW, the Hiram Percy Maxim Memorial Station at ARRL Headquarters in Newington, Connecticut.

During the 40-meter QSO, Sams relayed his appreciation for the history of the site, stating, "This historic site is listed on the National Register of Historic Places for its global importance in communication history." He also noted his time in the United States Navy and how critical it was to have two-way radio communications from ship-to-shore and ship-to-ship.