owned by their descendants. Scholarship The Texas Runaway Slave Project, located in Nacogdoches at the Stephen F. Austin State University, has researched runaway advertisements that appeared in 19,000 editions of newspapers from the mid-19th century. Alice L. Baumgartner has studied the prevalence of enslaved people who fled slavery from the Southern slave states to Mexico. She published South to Freedom: Runaway Slaves to Mexico and the Road to the Civil War. Thomas Mareite completed a doctoral dissertation at Leiden University on the social and political experiences of enslaved people who escaped from bondage from the US South to Mexico titled Conditional freedom : free soil and fugitive slaves from the US South to Mexico's Northeast, 1803-1861. Roseann Bacha-Garza, of the University of Texas Rio Grande Valley, has managed historical archeology projects and has researched the incidence of enslaved people who fled to Mexico. Maria Esther Hammack completed her doctoral dissertation titled South of Slavery: Freedom Fighters & Black Movement across a Global Frontier, 1790-1868 on the experiences and channels undertaken by freedom seekers, at the University of Texas at Austin. Mekala Audain recently published a chapter titled "A Scheme to Desert: The Louisiana Purchase and Freedom Seekers in the Louisiana-Texas Borderlands, 1804-1806" in the edited volume In Search of Liberty: African American Internationalism in the Nineteenth-Century Atlantic World. Audain discusses how a large number of freedom seekers had escaped Louisiana in 1804 and "did not associate freedom with the northern US, the Ohio River valley, or Canada; instead they looked to the US western frontier to find freedom." National Underground Railroad Network Following upon legislation passed in 1990 for the National Park Service to perform a special resource study of the Underground Railroad, in 1997, the 105th Congress introduced and subsequently passed H.R. 1635 – National Underground Railroad Network to Freedom Act of 1998, which President Bill Clinton signed into law in 1998. This act authorized the United States National Park Service to establish the National Underground Railroad Network to Freedom program to identify associated sites, as well as preserve them and popularize the Underground Railroad and stories of people involved in it. The National Park Service has designated many sites within the network, posted stories about people and places, sponsors an essay contest, and holds a national conference about the Underground Railroad in May or June each year. The Harriet Tubman Underground Railroad National Historical Park, which includes Underground