Newswise — The upcoming movie “12 Years A Slave” is winning raves for its unsparing portrayal of a free black man kidnapped into slavery in 1840s Louisiana, who later sues his captors in court.

Lea VanderVelde is familiar with cases like Solomon Northup’s, the movie’s hero. The University of Iowa law professor researches freedom suits, legal actions largely lost to history that were brought by slaves against their masters in hopes of gaining their freedom. She has visited dozens of county court houses throughout the Midwest during the last decade looking for records of the suits that were filed between the 1830s and 1858.

A book about her research, “Redemption Songs,” will be published next spring by Oxford University Press.

VanderVelde said the suits show that slaves attempted to use the courts to legally escape slavery to an extent people never knew before. "Our conception is that slaves either suffered or tried to escape," she said. "What we never knew was how many sought their freedom in court, and how many received it. When you read these lawsuits, you hear the voices of people rising up against enslavement in a way that's not heard by Americans today."

She said slaves who sued for their freedom generally argued that either they always were free and were being enslaved illegally, their master had died and they had been promised freedom upon his death, they attempted to buy their freedom but their master reneged on the deal, or they had visited a free state, which meant they were now free.

The most famous of these suits was brought by Dred Scott, a St. Louis slave who accompanied his master on trips to Illinois and parts of Wisconsin Territory that are today Minnesota. Since Illinois and Wisconsin Territory were free, Scott argued that he was no longer a slave, even after his return to slave territory. The suit and its appeals led to the infamous 1858 Supreme Court decision that denied Scott and all blacks the rights of citizenship, prohibited the federal government from banning slavery, and set the stage for the Civil War.

The Dred Scott Decision also said that blacks don't have access to the court system to seek their freedom, thus shutting off all future freedom suits. Before it, though, thousands of slaves filed suit in state and territorial courts to win their freedom.

VanderVelde's research has taken her to courthouses across the Midwest, looking in dusty basement for papers that haven't been touched since the 1850s. Her biggest cache was discovered at the courthouse in St. Louis where she discovered about 190 freedom suit files in 2002 (about 250 suits were filed in the state). Stored for more than a century in the courthouse's gritty, cobwebbed basement, the papers she discovered were yellowed and crumbling, some so badly they were sent to a specialist for preservation. Since the typewriter had not yet been invented, the motions, depositions, jury instructions and verdicts are all handwritten, often in an illegible scrawl.

In the process of her research, VanderVelde has brought back many of the voices of the slaves the war was fought to free. Marie, in her suit, says she was "assaulted, beaten, bruised, ill-treated and faces imprisonment." John Singleton, born a free man in Illinois, was kidnapped as a teenager and sold into slavery in the South. Leman Dutton was born of a free woman, making her free, too, but her mother's former owner refused to grant the child freedom and kept her as a slave.

There was Hannah, who says she was "treated with great cruelty and oppression by John Pitcher," her owner, after she had the temerity to sue Pitcher for her freedom. James Wilkinson was not only enslaved but a victim of fraud after his owner, Aaron Young, reneged on an agreement to let Wilkinson buy his freedom for $200.

Four years after the last payment was made, Young still had not freed Wilkinson.