Only feet from the judges, Alexandra Nichols clutched a redheaded doll and struggled to articulate her words, each consonant sticking in her throat before being coughed out in a clipped wheeze.

But she wasn't nervous -- she was portraying a 12-year-old Ukrainian immigrant.

Wearing a long gray skirt and her great-grandmother's embroidered blouse, Alexandra and her partner, Jacqueline Rice, played Ukrainians, Italians and Britons newly arrived on Ellis Island as part of the National History Day finals last week at the University of Maryland at College Park. Their performance, "America Is Not Merely a Nation, but a Teeming Nation of Nations," highlighted immigrant stories from 1892 to 1924.

Her 13-year-old brother, Andrew -- in his fourth year of watching his sister perform -- sat amid the audience's bleak white chairs. He wore gangster-like garb, a brown barrel hat over his dark eyebrows, because he too was part of the competition. Alexandra and Andrew are part of a growing body of siblings participating each year in National History Day.

"It is a growing trend across the country," said Mark Robinson, public relations director of National History Day, a nationwide education program that hosts the final competition in College Park. "It breeds families doing family history and students becoming more active in understanding what their family history is."

In Calvert County alone, eight pairs of siblings -- including the Nicholses -- took part at the county or state level. Three of them advanced to the finals last week.

"In any given year, just at our county fair, it is probably anywhere between as many as 15 to 25 [sibling] sets," said Scott McComb, the Calvert County coordinator for National History Day.

Of the 2,057 national finalists, there were about 75 to 80 sibling sets, Executive Director Cathy Gorn said.

"Parents who have older siblings who had good experiences encourage younger siblings to get involved," said Barbara Smith, a social studies teacher at Northern Middle School in Calvert County who advised Andrew Nichols. "In some cases they may plan the summer vacation around the history fair project."

The Nichols and Rice families -- 13 people in all -- traveled together to Ellis Island to see the immigrant entry point firsthand. One family in the competition even flew to Normandy, France, for a project, Gorn said.

Calvert County twins Billy and Kristin Hay, who made the finals this year, ventured to Philadelphia for research on their exhibit, "In Search of the Northwest Passage: Success or Failure?"

By working together, the Hays were able to combine their talents and consolidate their family computer resources to make an exhibit that showcased representations of Lewis and Clark findings.

"With twins, in the case of Billy and Kristin, they are quite opposite from each other," said Merry Ellen Fallica, a social studies teacher at Plum Point Middle School who advised the Hay siblings. "One has the creative force, and one has the technical force, so they can enhance each other's work."

Teaming up also meant that the twins' family could concentrate on one project and travel to the same locations, avoid conflicts over the family computer and bounce the siblings' ideas off each other.

"They haven't killed each other yet," said their mother, Holly Hay.

The Nicholses -- Andrew silent, leaving the speaking to his sister -- don't plan to make a brother-sister team.

"I think that would be a combination of death," Alexandra said.

But as a seasoned competitor, she gives her brother tips, "mostly on stage presence," said Alexandra, whose blond hair was pulled back in a tight ponytail.

One National History Day sibling from more than 10 years ago never left the program. Robinson, now public relations director, once produced a project with his brother on their ancestor D.E. Hutinson, a pioneer in conservation.

"It's the 'Hotel California,' " he said of National History Day. "Once you're in, you'll never get out."

Projects on family history often draw students' distant relatives into the program.

"It involves the extended families too, the grandparents, the aunts, the uncles, finding out about their family history," Fallica said. "The only complaint [from a student] I got was, 'I talked to my grandfather so long my mom said the phone bill would be high.' "

Fallica has advised, judged and parented History Day competitors during her 27 years as a social studies teacher in Calvert County. Siblings involved in National History Day, she said, have included her four children.

"Every year I usually [advise] one or two sibling teams," Fallica said. "It is really a whole family thing."

Some families have become "dynasties" of the National History Day, said Gorn, the executive director. For the Frese family of Marshalltown, Iowa, the dynasty began with Sarah, now 17, continued at last week's finals with Stephen, 15, and will be kept alive by 8-year-old Rebekah.

"We look at athletics and how that often becomes a family thing," Smith said. "This is a niche for many kids who aren't involved in sports or music."

And team members who are not related can become almost like family, even with their partners' brothers and sisters.

In Andrew, her partner's brother, Jacqueline has found a new sibling.

"He bugs her as much as me now," Alexandra said.

Alexandra Nichols changes into her costume as her partner, Jacqueline Rice, performs during the National History Day competition in College Park. Alexandra, center, and her brother Andrew were among about 75 to 80 sibling sets in the event. At left is Alexandra's partner, Jacqueline.