It is 5 a.m. While many St. Louisans sleep, a dozen or so couples board a chartered bus. Destination: Iowa City, Iowa. In the darkness of the morning, one carries a pillow for comfort on the nine-hour round trip, another has a tuxedo folded over his arm, and still another is cradling a sleeping child.

They are not unlike the civil rights pioneers who traveled the Underground Railroad to freedom. They are just of another era, with cell phones, digital cameras and iPods.

Still, their journey is to achieve a status that is not lawful within the borders of their state. Same-sex couples are prohibited from getting married in Missouri.

They are taking the Show Me Marriage Equality Bus to Iowa.

When they return late that evening, they will exit the bus, two by two. But something will be very different. They will be married — at least in the great state of Iowa, where same-sex marriage is permitted and legal.

Organized by St. Louis gay activists Ed Reggi and Scott Emanuel, the Show Me Marriage Equality Bus has made three trips to Iowa since its inaugural journey in May 2009.

For noted playwright, director, and civil rights activist Joan Lipkin, artistic director of St. Louis’ That Uppity Theatre Company, the historic bus trip was just the ticket to galvanize her latest production.

“I have been thinking about the changing face of marriage for some time — its history of often being based on property, the escalating divorce rate, as well as the increased interest in same-sex marriage,” Lipkin said. “When Prop 8 passed in Nov. 2008 and the right to same-sex marriage in California was repealed, as it subsequently was in Maine, it became increasingly clear to me that in some significant ways, the rights of LGBT citizens were diminishing rather than advancing.”

Thus, Lipkin — whose award-winning body of LGBT-themed theatrical works includes Some of My Best Friends Are…, Small Domestic Acts, The Date, and Beyond Stonewall: Why We March — had the inspiration for her latest play. She planned to tell the story of the bus trip to Iowa within the larger structure of a heterosexual couple’s wedding.

Lipkin says her initial image for the play was an earthquake that interrupts the traditional bridal walk down the aisle.

“It is as if the world is cracking open, and indeed, it is,” Lipkin said. “I do not believe that the legalization of same-sex marriage in any way threatens heterosexual marriage. But as marriage is at the center of our collective imagination and considered to be a significant rite of passage, LGBT Americans will never be full citizens until they are accorded this right. I also believe that some of the bigotry aimed at lesbians and gays will diminish if they are allowed to marry.”

This belief is shared by many of the play’s cast members.

For Sara Hamilton, 31, who is raising a son with Shanon Hamilton, her partner of six years, acting in this piece has particular relevance.

“I have experienced many of the ups and downs that the characters in this show struggle with,” Hamilton said.

Keith Thompson, 46, a financial adviser, took part in the first Marriage Equality Bus in May 2009, despite having had a commitment ceremony in 1997. He has been with his partner, Dan Dowd, a church administrator, for 23 years.

An actor who specializes in musical theater, Thompson came out of 10 years of semi-retirement to do the show.

“We decided to marry in Iowa to take one small step toward true marriage equality for future generations,” Thompson said. “We were married in 1997 in front of our family, friends and God, but we didn’t have the legal rights.”

For Thompson, involvement in the play has deepened appreciation of his decision to marry.

“I’ve learned while working on The State of Marriage what an important civil rights action we actually took,” Thompson said. “Our marriage certificate from Iowa hangs framed in our bedroom. Every time I look at it, I smile.”

Not everyone in the production identifies as LGBT. Theresa Masters, 43, is a computer instructor by day and a performer by night. She has been married to musician Larry Kornfeld, 50, for 15 years.

“I am always eager to work with Joan,” Masters said. “She allows her actors to be such a fundamental part in the creation of the show. Plus, I find the presentation of the message in this piece to be both humorous and poignant, a hallmark of her inventive work.”

In writing The State of Marriage, Lipkin incorporated real stories of the couples who tied the knot in Iowa.

Colin Murphy and Kurt Ross, his partner of 12 years, are one such couple. In March, the duo boarded the Show Me Marriage Equality Bus for its third trip. A senior writer for the Vital Voice, an LGBT publication in St. Louis, and author of the column “One Out of Ten Ain’t Bad,” Murphy said that he was stunned by how much he was impacted by the short, simple ceremony.

“With us were the generations of gay, lesbian, bisexual and transgender individuals who did not live to see this day,” Murphy said. “We also walked down the aisle with future generations in mind — generations who will no doubt marvel that we had to leave family and friends behind and drive to another state to be married.”

The civil rights movements of black people and women are also far from over, but progress has been made in many areas of law and culture. The gap between women’s income and men’s income is closing, and many years have passed since laws forbidding interracial marriages existed.

Today’s most dynamic movement is about LGBT rights. There are 1,138 federal benefits that heterosexual married couples enjoy that same-sex couples do not, simply because the latter cannot get married.

Because the play deconstructs marriage, Lipkin says that the form of the piece is unconventional as well. Regionally acclaimed drag performer Leon Braxton (a.k.a. Dieta Pepsi) heads a Greek chorus of bridesmaids that includes Hamilton and Masters.

At times, the theatrical fourth wall is fractured when performers ask audience members to read some of the benefits denied to same-sex couples or offer them wedding cake and then retract it.

“I believe that often the more difficult and complicated the subject matter, the more important it is to provide a humorous way to engage rather than threaten audiences,” Lipkin said.

Like the arts in general, theater is often ahead of the law. This will be especially true when The State of Marriage opens June 10.

Conceived and directed by Lipkin in collaboration with J.T. Ricroft and a co-production of That Uppity Theatre Company and St. Louis Actors’ Studio, The State of Marriage will run Thursdays through Sundays, June 10-20. It will be performed at the Regional Arts Commission Building, 128 Delmar Blvd., in St. Louis. To purchase tickets, go to stlas.com, the St. Louis Actors’ Studio’s website.

A family law attorney in Clayton, Mo., Susan E. Block is a former circuit judge. She has contributed to many publications, including the St. Louis Post-Dispatch and the St. Louis Beacon, and is a commentator for KSDK-TV’s “I’m Just Sayin” segment.