In 1856, George Corson, a cofounder of the Plymouth Meeting Anti-Slavery Society, transformed the carriage shed attached to his stone barn into an abolitionist lecture hall. Corson's decision was part of a much larger antislavery commitment that included sheltering fugitive slaves.

Outraged by the federal Fugitive Slave Act of 1850, Corson, like other abolitionist Quakers, actively opposed the unjust law by holding antislavery meetings and serving as an agent on the Underground Railroad.

Since that time, Abolition Hall, at the intersection of Butler and Germantown Pikes, has served as an enduring reminder that we as American citizens have a moral obligation to oppose and defeat any unjust law enacted by our federal government.

But if K. Hovnanian Homes has its way, Abolition Hall and nearby historical structures that are related to it will be compromised by the development of 48 townhouses.

As a Quaker historian, I am extremely concerned about any plan requiring the rerouting of Butler Pike between the Corson homestead and Abolition Hall, sites that are listed on the National Register of Historic Places. The road realignment would also require the removal of the Plymouth Meeting Country Store and Post Office, which is also listed on the National Register.

Whitemarsh Township officials need to understand the powerful significance of the history that occurred in their own backyard.

The Underground Railroad was a clandestine - and illegal - network of African American and white abolitionists who assisted slaves escaping bondage in the antebellum South to freedom in the North. It operated in direct violation of the fugitive slave law, which required public officials and all citizens of free states to assist federal marshals in the recapture of a runaway slave or face a fine of $1,000. In addition, the law stipulated that any person aiding a runaway slave by providing food or shelter was subject to six months' imprisonment and a $1,000 fine.

While historians estimate that only 100,000 of nearly four million slaves actually escaped on the Underground Railroad, it represents an early effort at civil disobedience, as well as the first time blacks and whites joined together in a common struggle for human rights.

Plymouth Meeting's Abolition Hall was at the center of that historic movement. Not only did the structure accommodate 200 persons who gathered to listen to such prominent abolitionists as Lucretia Mott and William Lloyd Garrison, but it was also an important stop on the Underground Railroad.

Corson, who was white, maintained contacts with Dan Ross, a black conductor who lived in Norristown, and William Still, the free black clerk of the Pennsylvania Anti-Slavery Society who coordinated the eastern line of the Underground Railroad from his office at 31 N. Fifth St. in Philadelphia.

Ross and Still sent fugitives to Corson, who hid them in Abolition Hall. When the runaways were pursued by a slave catcher, Corson shuttled them off to the Plymouth Meeting Country Store via a tunnel. So effective was this arrangement that fugitives felt "that no slave hunter would catch them as long as they were under Corson's care," according to Still, in his 1871 book, The Underground Railroad.

Having spent many years researching and writing about - and trying to preserve - historic structures related to Pennsylvania's Underground Railroad, I know that even if the Corson homestead, Abolition Hall, and the Plymouth Meeting Country Store are not demolished, the historical integrity of the properties would be severely compromised by the developer's plans.

Preserving that integrity is why, in 1971, they were placed on the National Register. It's why the Pennsylvania Historical and Museum Commission issued a letter to Plymouth and Whitemarsh Townships clarifying and reiterating the "historical and architectural significance" of the "inter-related complex of buildings."

That history is under threat, as evidenced by Preservation Pennsylvania adding the property to its 2017 at-risk list, citing the possibility of a "compromised setting" due to potential residential development and road realignment.

If Whitemarsh Township hopes to preserve the powerful history that took place there, it should prevent the development of the Corson property.

William C. Kashatus is the author of "Just Over the Line: Chester County and the Underground Railroad." bill@historylive,net