American University journalism professor Rodger Streitmatter has been chronicling gay America for years. His latest, Outlaw Marriages, hits just days after president Obama announced his support of gay marriage. In the book, Streitmatter chronicles the public and private lives of 15 same sex couples, leaning heavily on artists—among them Walt Whitman, Greta Garbo, and Jasper Johns.

Do you think Obama's endorsement of gay marriage is a tipping point?

Obama’s announcement is absolutely huge. I think it will go down in history as an instance when a president had the courage to throw his weight behind an initiative that he believed in—that he wanted to be on the right side of—even if the political consequences were uncertain. It will definitely energize the LGBT community, as well as a lot of young people who are strong supporters of gay marriage. Lots of people are saying, “This is great. The guy I voted for in 2008 is back—somebody who’s committed to change and somebody I can believe in!”

I think it also will have impact on people who are still on the fence on the gay marriage issue. Obama’s announcement will nudge a lot of people—people who respect him—to commit themselves to this issue.

What was the catalyst for writing this book?

Same-sex marriage has been in the national spotlight for about a dozen years. Lots of books have been written about the topic as a political issue, and there also have been books about the legal questions and the religious angle. But there hasn’t been much at all written about what I would call the “personal” dimensions of the issue.

I’ve been in a same-sex relationship for the last 29 years, and so I know how important that personal piece of the story is. I know that my partner—now my husband—has played a crucial role in my life, and I know I’ve done the same for his. So I wanted to bring that human element into the conversation. I wanted to document that the partners in a same-sex relationship can contribute enormously to each other’s well being—as well as to the culture writ large.

In researching this book, whose story surprised you the most?

I love the story of Tennessee Williams and Frank Merlo. Williams won the Pulitzer Prize for A Streetcar Named Desire in early 1948. But then he went into this downward spiral—he became addicted to drugs and casual sex—to the point that he said, in his personal journal, that he would never write another play.

Then he fell in love with this hunky guy named Frank Merlo—the night they met, they had sex on the dunes in Provincetown. Merlo was a World War II vet who was working as a truck driver. So this rock-solid guy—with no education beyond high school—took it upon himself to bring order to Williams’s life. He single-handedly weaned Williams off the drugs and put an end to the casual sex so this world-class playwright could return to his writing.

I just love the idea of this truck driver taking control of Williams’s life. If it hadn’t been for Frank Merlo, Williams never would have written Cat on a Hot Tin Roof.

How familiar were you with these couples before you began working on the book?

One of the things I love about writing books is that it allows me to learn so much. Before I started this book, the only gay couple from the past that I knew about was Gertrude Stein and Alice B. Toklas. So every other couple in the book was entirely new territory for me. I loved learning about them.

Were any of these couples able to express themselves publicly? Did any formalize their affairs with a ceremony?

I’d say that Gertrude Stein and Alice B. Toklas win the trophy for being the most “out” of the couples. They lived together unapologetically as a lesbian couple—Gertrude called herself the husband and Alice the wife—for 40 years. When Gertrude went on a nationwide book tour in 1934 and was invited to the White House, she automatically took Alice with her. And when she posed for photos, she insisted that Alice was standing right there beside her—and that was 70 years before same-sex couples were recognized in this country.