During her 26 years as an elementary public school teacher, Barbara Vogel has comforted her students through the horrors of the Challenger space shuttle explosion, Oklahoma City federal building bombing, and multiple school shootings. But she says nothing prepared her for the response of her fifth-grade students at Highline Community School in Aurora, Colorado, to a newspaper article she read to them on slavery in Sudan.

"They sat at my feet and tears streamed down their faces," Vogel recalls. It happened in February 1998, just after the students had studied the Civil War. "They thought slavery was over. So did I," Vogel says. "The first thing they said was, 'What are we going to do about this?' " Vogel did not want to stand in the way of her students' idealism and budding sense of citizenship. "We became instant abolitionists," she says.

Following one of their class rules, "Do small things with great love," a quotation from Mother Teresa that hangs across five feet of the classroom wall, the students soon discovered through Internet research that the Swiss group Christian Solidarity International (CSI) buys back Sudanese slaves for about $50 each, and a Boston-based organization, the American Anti-Slavery Group, raises money for CSI's slavery redemption efforts. They studied the United Nations' Declaration on Human Rights. "These are all God's people, and you do not own another person," Vogel says.

The students began to wonder if they could buy back a slave. They launched a STOP (Slavery That Oppresses People) campaign, writing thousands of letters to government leaders and celebrities such as President Clinton, Steven Spielberg, and Oprah Winfrey. They collected allowance money, organized lemonade-stand sales, and sold used ...