The two were both struggling actors when they met in 1952. Rowan had sold his interest in a used car dealership to take acting lessons, and Martin, who had written gags for TV shows and comedians, was tending bar in Los Angeles to pay the rent. Rowan, hearing Martin was looking for a comedy partner, visited him at the bar, where he found him eating a banana. "Why are you eating a banana?" he asked. "If you've ever eaten here, you'd know what's with the banana," he replied, and a comedy team was born.
Here's a short Laugh In clip that includes one of Rowan & Martin's opening bits.
And if you were a fan, here's a longer clip of "Laugh In" out takes. You knew it had to be like this behind the camera. Their show was the first show that both the kids and their parents laughed at. It was really a bridge between the generations. Programming certainly changed after it's run.