KAREN GRIGSBY BATES, BYLINE: I'm Karen Grigsby Bates and that, of course, is the theme song to "I Love Lucy," one of the most popular shows in the history of television. Its stars, redheaded Lucille Ball and her Cuban-American husband, Desi Arnaz, became TV icons. But they almost didn't get on TV.

Kathleen Brady is the author of "Lucille: the Life of Lucille Ball." Brady says the network that wanted Ball to star in her own sitcom was not interested in her husband.

KATHLEEN BRADY: CBS and the sponsor, Philip Morris cigarettes, were adamantly opposed to this. They said that the American public would not accept Desi as the husband of a red-blooded, American girl.

BATES: Ball told the network they'd have both of them or neither and eventually, CBS gave in despite its reservations about Arnaz's Cuban heritage and, Brady says, something else.

BRADY: As we all know, Desi had a fairly strong accent.

(SOUNDBITE OF TV SHOW, "I LOVE LUCY")

DESI ARNAZ: (As Ricky Ricardo) What's the matter with the way I talk?

LUCILLE BALL: (As Lucy Ricardo) Well, I haven't told you this before, dear, but you speak with a slight accent.

(AUDIENCE LAUGHTER)

BATES: The show was a hit for six years, and more than a half-century later still runs in syndication, where lines like this have become famous:

(SOUNDBITE OF TV SHOW, "I LOVE LUCY")

ARNAZ: (As Ricky) Lucy, I'm home.

BATES: Flash forward to the early '70s, where the war for civil rights had been waged, segregation had been abolished - on paper, anyway - and social upheaval convulsed several cities. Television got a little grittier when "All in the Family" debuted with a blue-collar philosopher named Archie Bunker. Archie was having a hard time keeping up with the country's rapid evolution. The Supreme Court had declared anti-miscegenation laws illegal when it decided Loving v. Virginia, and Archie, like a lot of America, was worried about the multihued future.

(SOUNDBITE OF TV SHOW, ALL IN THE FAMILY")

CARROLL O'CONNOR: (As Archie Bunker) All this business of mixing the colors. You go on with that, the first thing you know, the whole world's going to be one color.

JEAN STAPLETON: (As Edith Bunker) Well, what's wrong with that, Archie?

O'CONNOR: (As Archie) Can't you use your head? How the hell are we going to tell each other apart?

(AUDIENCE LAUGHTER)

BATES: And to show that sentiment wasn't a one-way street, we get Archie's black neighbor, George Jefferson. George was not a kumbaya-kind of guy. So when he learns his son Lionel's fiancee has a white father, George explodes.

(SOUNDBITE OF TV SHOW, ALL IN THE FAMILY")

SHERMAN HELMSLEY: (As George Jefferson) I don't want no white in-laws in my family.

MIKE EVANS: (As Lionel Jefferson) But they're going to be my in-laws, not yours.

HELMSLEY: (As George) But think, son, think. What about your children? What they going to be?

EVANS: (As Lionel) Well, boys and girls, I hope.

(AUDIENCE LAUGHTER)

BATES: Shows like this were helping America sort through its conflicted emotions and anxieties about our changing racial profile. While showing an interracial couple on the "Jeffersons" was considered daring in the mid-'70s, today interracial couples are, if not common, no big deal on TV. The WASP-y lead couple on ABC's popular medical drama "Grey's Anatomy" fell in love with an Ethiopian orphan who came to their Seattle hospital for treatment.

(SOUNDBITE OF TV SHOW, "GREY'S ANATOMY")

PATRICK DEMPSEY: (As Dr. Shepherd) we've been trying so hard to start a family, and she needs one...

BATES: So although George Jefferson would have been appalled, little Zola joined the Shepherd household. Another family on the series has a Latina mom, whose wife is white, and a half-Latina daughter from a previous union. No big deal. The comedy "Modern Family" features a gay couple with an adopted Vietnamese daughter, and a blended family that has white, Latino and multiethnic members although here, race and ethnicity are usually used as a throwaway line. Here's Gloria Delgado-Pritchett, explaining why she's sulking.

(SOUNDBITE OF TV SHOW, "MODERN FAMILY")

SOFIA VEGARA: (As Gloria Delgado-Pritchett) I shouldn't be so angry but I am Latin, so I get to feel whatever I want.

BATES: And by the way: nobody's complaining about Sophia Vegara's accent. Marcia Dawkins teaches the impact of race on society at the University of Southern California. She says seeing these different family configurations reflected in popular culture is a good thing for Americans.

MARCIA DAWKINS: Research certainly indicates that these type of images can sensitize viewing audiences to the existence of these types of families.

BATES: And sensitize them to some of the complicated challenges such families face. In NBC's drama "Parenthood," Jasmine and Crosby Braverman try to figure out how to tell their 8-year-old son, Jabbar, the meaning of a racial slur. Jasmine insists on taking the lead in the talk. Crosby is irritated, but Jasmine says in this matter, her wishes outweigh his.

(SOUNDBITE OF TV SHOW, PARENTHOOD")

DAX SHEPARD: (As Crosby Braverman) Because you're black, yeah, I feel like you've pulled rank.

JOY BRYANT: (As Jasmine Braverman) Baby, you have to respect the fact that I have an understanding on the subject that you don't. And the fact is, that word means something different to Jabbar because he's black.

BATES: Or technically, biracial - which, Jasmine points out, won't do much to protect him from bias. Having more visibility for interracial and interethnic families is important, says USC's Dawkins, but how they're shown is as important as the fact that they're shown.

DAWKINS: It's not just seeing these families that makes them believable, right? It's seeing how they interact with each other every day, what they're dealing with in terms of society, what possibilities they have, what special challenges they have as a family.

BATES: All things that make these TV families, at bottom, very much like the families watching them on the other side of the screen.

Karen Grigsby Bates, NPR News.