The first mobile phone call was made 40 years today, on April 3, 1973, by Motorola employee Martin Cooper. Using a prototype of what would become the Motorola DynaTAC 8000x, the world’s first commercial cell phone, Cooper stood near a 900 MHz base station on Sixth Avenue, between 53rd and 54th Streets, in New York City and placed a call to the headquarters of Bell Labs in New Jersey.

The substance of the call is lost to history, but it probably doesn’t compare to the first telegram (“What hath God wrought”), first telephone call (“Mr. Watson, come here, I want to see you”), or even the first text message (“Merry Christmas”). Cooper’s inaugural mobile conversation is remembered as, “I’m ringing you just to see if my call sounds good at your end,’ or something to that effect.”

Regardless, the call was a major step in the development of mobile technology, though it would take another decade for the DynaTAC to reach consumers and two more decades for cell phones to overtake land lines in worldwide usage. But today, “phone” is synonymous with “mobile phone,” and the latest trend is toward mobile devices that aren’t really phones much at all. Motorola’s mobile business, meanwhile, is now owned by Google.