Amy Crampton and Tonya Agnew of Lafayette, Ind., plan to marry outside the U.S. Supreme Court on March 26. (Photo courtesy of Tonya Agnew)

Lafayette, Ind., residents Tonya Agnew and Amy Crampton plan to travel to Washington this weekend ahead of the U.S. Supreme Court’s oral arguments in the two cases that challenge the constitutionality of California’s Proposition 8 and the Defense of Marriage Act.

The couple’s 9-year-old son Leo is what Agnew describes as a “history buff.” But she and her partner of nearly 15 years have another thing on their agenda while in the nation’s capital.

“We thought it would be an amazing experience for him and for us to be part of history and see what’s happening and just be part of the vibe in town,” Agnew says. “Our next thought was kind of like, ‘Oh well we should totally get married while we’re there.’”

Agnew and Crampton plan to exchange vows at the Supreme Court on Tuesday against the backdrop of a rally in support of marriage rights for same-sex couples that is expected to draw thousands. Opponents of nuptials for gays and lesbians on the same day are scheduled to march to the court as the justices begin to hold oral arguments on the Prop 8 case.

Same-sex marriage supporters are expected to once again gather outside the court on Wednesday before oral arguments in the case that challenges DOMA.

“I’m cautiously optimistic,” Agnew says. “[I’m] really just mostly excited to be there and the fact that they’re even hearing them to begin with is just incredible.”

Marriage Equality USA Board President Cathy Marino-Thomas plans to travel from New York to D.C. on Monday with her wife Sheila, their 13-year-old daughter Jackie and other same-sex marriage advocates.

She was among those who spearheaded the years-long campaign for nuptials for gays and lesbians in New York that culminated in 2011 with Gov. Andrew Cuomo signing the same-sex marriage bill the state Senate narrowly approved into law.

Marino-Thomas says from her Manhattan office she has a “really, really positive feeling about this.”

“In the beginning it was just a small group of LGBT people who believed in the right to marry,” she says. “We graduated and more of our community believed in it. Then as time went on we started to gather straight supporters and then we started to gather politicians — Democrats, and the next step was we started to get some Republican support. Now we’re reading about the conservative argument for marriage equality and somebody like Ted Olson is leading the charge on one of the marriage cases. People are coming out for marriage left and right.”

Caleb-Michael Files, a junior at the University of Missouri-Kansas City, was in D.C. when the Supreme Court heard oral arguments in the case that challenged President Obama’s health care reform law. He was also here last June when the justices issued their 5-4 ruling that narrowly upheld it.

The Knob Noster, Mo., native, who says his family did not accept him growing up because of his sexual orientation, plans to return to D.C. in time for the oral arguments in the Prop 8 case.

“These are important milestones that we have to be present for and understand what’s going on,” Files says.

Rallies, vigils planned across the country

The two rallies outside the Supreme Court are among the more than 170 events scheduled to take place across the country to coincide with the oral arguments.

The School Without Walls GSA in D.C. will hold a candlelight vigil and rally in front of the Supreme Court on Monday. Retired New Hampshire Bishop V. Gene Robinson is among those scheduled to attend an inter-faith service at the Lutheran Church of the Reformation on Capitol Hill on Tuesday.

Other gatherings are scheduled to take place in Cumberland, Md.; Richmond, Va.; and Keyser, W.Va.

Up to 30 people are expected to attend a candlelight vigil on the beach in Gulfport, Miss., on Tuesday.

Leiana Wortel, who tried to apply for a marriage license with her partner and four other same-sex couples in Hattiesburg, Miss., in January as part of the Campaign for Southern Equality’s efforts to highlight the lack of marriage rights for gays and lesbians in the South, decided to organize the event after she learned about other gatherings around the upcoming oral arguments in the DOMA and Prop 8 cases.

“We just thought it would be nice to do something on the coast to get more of the local LGBT community involved and start some conversation here,” Wortel says.

An estimated 500 people are expected to attend a rally in support of marriage rights for same-sex couples at Federal Plaza in downtown Chicago on Monday.

Local LGBT rights advocate Richard Streetman expects the gathering could draw even more people if the Illinois House of Representatives this week approves a bill that would allow gays and lesbians to tie the knot in the state.

“Throughout the history of LGBT Americans, we have gathered in Washington, D.C., to petition our government,” he says. “There are times where that’s necessary. There are times when people should be working in their home communities.”

Advocates remain cautiously optimistic

Nine states and D.C. currently allow same-sex marriage.

A Rhode Island Senate committee on Thursday will hold a hearing on a bill that would allow gays and lesbians to marry in the Ocean State. Lawmakers in Delaware, Minnesota and New Jersey in the coming weeks and months are expected to consider measures that would extend marriage rights to same-sex couples.

Illinois Gov. Pat Quinn has said he will sign a same-sex marriage bill into law, but Streetman pointed out DOMA will remain on the books even if gays and lesbians can marry in the state.

“People in Illinois are excited,” he says about the outcome of the DOMA and Prop 8 cases. “Some people have unrealistic expectations of states giving us our state rights. It is almost symbolic until you deal with DOMA.”

Mississippi and Missouri are among the 31 states that have constitutionally banned same-sex marriage.

Wortel says a lot of people with whom she speaks “are optimistic” the justices will find Prop 8 and DOMA unconstitutional. She remains less hopeful about the prospect of nuptials for gays and lesbians in the Magnolia State.

“People are not as optimistic of what the outcome will necessarily be in Mississippi,” Wortel says.

Files notes questions over the future of Missouri’s constitutional ban on same-sex marriage if the justices strike down DOMA persist — Republicans control both chambers of the state Legislature, but a civil unions bill could be introduced once the Supreme Court rules on Prop 8 and DOMA.

“After the Affordable Health Care ruling, I think people are optimistic that there’s been a turning tide with the Supreme Court,” Files says. “These kinds of social and health care issues are issues we’re moving a little bit to the left on.”

Indiana lawmakers last month postponed a debate on a proposed constitutional amendment that would ban same-sex marriage until the outcome of the DOMA and Prop 8 cases is clear.

Agnew said she hopes they “really squash the current efforts underway” to amend the state constitution.

“That was exciting for us,” she says of the delayed debate in Indianapolis. “We’re hoping that it will be a positive outcome and will really trickle down to everyone — all of us out here in the Midwest and elsewhere.”