NBC News: A new documentary based on a vast collection of old photos featuring gay men in love going back to the mid-1800s has made its television debut.

"100 Years of Men in Love: The Accidental Collection," directed by Emmy-winning producer David Millbern, is based on the photo book "Loving: A Photographic History of Men in Love, 1850s - 1950s" by Hugh Nini and Neal Treadwell.

Nini and Treadwell began their collection 22 years ago when the couple stumbled upon a rare, century-old photo of a gay couple in an antique shop. Since then, the men have been collecting thousands of images of gay men dating that go back 170 years.

To date, they hold a collection of approximately 3,000 photos from around the world, and they're not done collecting yet. (To see their story on Youtube, Click Here.)