It was all about puppies.

Well, that's not true. It was actually all about "The Puppy Episode," which sounded innocent enough, but wasn't—not in 1997. The episode, part of comedian Ellen DeGeneres's eponymous '90s sitcom, featured DeGeneres kissing actress Laura Dern.

In prime time. On national television.

That legendary April 30 episode was the highest-rated Ellen, and it featured cameos by fellow lesbians k.d. lang and Melissa Etheridge (but, in the end, no puppies). In it, Ellen's character—Ellen Morgan—meets Dern's character, a lesbian television producer named Susan. Morgan is attracted to Susan, discusses the situation with her therapist (played by Oprah), and realizes she's gay. She tells her friends—who are supportive and not at all surprised (hello, it's Ellen)—and dashes off to tell Susan before the woman leaves town.

This episode (which later won an Emmy) was a huge deal, especially in the lesbian community—gay bars around the country threw Ellen viewing parties, realizing that DeGeneres was poised to become the first openly gay person to play a gay character on TV. And the episode itself played into the anticipation, kicking off with Ellen in the bathroom, getting ready for a date. Her friends get impatient, and demand, "Ellen, are you coming out or not?" and, "Yeah, quit jerking us around and come out already!" Ellen's character peeks out of the bathroom and says, "What's the big deal; I've got a whole hour!"

Just before her character came out on the show—over an airport loudspeaker, no less—DeGeneres came out in real life, too (on Oprah, in fact). She was featured on the cover of Time magazine, under the headline "Yep, I'm Gay," and her relationship with actress Anne Heche was splashed all over the tabloids. Not surprisingly, she earned Jerry Falwell's disdain (he dubbed her "Ellen Degenerate").

And of course, she became an instant gay icon.

Then it all fell apart. DeGeneres's groundbreaking move ruined her career for years (and even Dern, who's straight, has admitted she had trouble getting work after kissing Ellen, thanks to the homophobic backlash). DeGeneres's sitcom was canceled the next season, and she didn't fully rebound until 2003, when she did the voice of Dory the fish in Finding Nemo, and launched her successful daytime talk show. After a dark period, it was nice to see DeGeneres finding something of a silver lining. Here's another somewhat silver lining to this rocky tale: If it weren't for Ellen coming out on national television in 1997, we might never have had Will & Grace.