Warren Buffett and Bill Gates first met at a 4th of July celebration. Here's how they became billionaire buddies.

Paul Sakuma/AP Photo

• Warren Buffett and Bill Gates were introduced to each other at a Fourth of July celebration in 1991.
• The legendary investor and the Microsoft cofounder expected to have little in common.
• Yet Buffett and Gates hit it off and became close friends and philanthropic partners.

Warren Buffett and Bill Gates might be the best-known billionaire buddies on the planet. Their famous friendship began over three decades ago on Fourth of July weekend...