Auto-correct and “Angry Birds.” GPS, and those awkward texts from last night.

Mobile phones, and their promise of unprecedented connectivity, have altered the way we live. And it all started 40 years ago today.

That’s when Martin Cooper, a vice president at Motorola, stepped onto a New York City sidewalk and made the first known cellphone call in history. And, whether you thank him or blame him, we haven’t stopped talking, texting and tweeting since.

In the time since Cooper brandished what would become the DynaTAC phone, our mobiles have gone from now-laughably clunky bricks to sleek, stylized slivers of technology. Now they’re becoming fashionably monstrous with phone-tablet hybrids like the Galaxy Note.

And, along the way, they’ve changed everything.

“We knew that someday everybody would have a (cell) phone, but it was hard to imagine that that would happen in my lifetime,” Cooper said to CNN last year. “And now we’ve got almost five billion phones in the world. Wow.”

Cooper and his team had been in a race with AT&T’s Bell Labs to create a cellphone. They’d worked for about three months on the model he walked outside with on April 3, 1973.

And that first call? It was to AT&T’s Joel Engell, who headed up Bell Labs.

“I called and told him, ‘Joel, I’m calling you from a cellular phone, a real cellular phone, a handheld, portable, real cellular phone’,” Cooper recalled.

And, as he recalls it, his rival wasn’t quite as talkative.

“I don’t remember exactly what he said, but it was really quiet for a while,” he said. “My assumption was that he was grinding his teeth. He was very polite and ended the call. When asked about it, he says he has no recollection of this moment.”

It would take 10 years for a version of that DynaTAC (Dynamic Adaptive Total Area Coverage) phone to hit the market, for a hefty $3,900. The kind of phone Gordon Gekko wielded in “Wall Street,” it weighed 2.5 pounds and was about a foot tall.

Compare that to the iPhone 5, which weighs in at under 4 ounces, is less than 5 inches from top to bottom and sells at prices starting at $199.

Not that Cooper, now 84, necessarily embraces every aspect of the latest advances in the field he helped create.

“I must tell you as much as we were dreamers, we never imagined that all these things could be combined into one. And I’m really not so sure that it’s a great thing,” he said. “Phones have gotten so complicated, so hard to use, that you wonder if this is designed for real people or for engineers.”

Doug Gross | CNN