New Philadelphia, Ill., was "the first town in the United States planned and legally registered by an African-American," writes University of Illinois Professor Chris Fennell in the journal Historical Archaeology.
It was founded in 1836 by Frank McWorter, a Kentucky slave who purchased his wife's freedom and then his own. He bartered for land in Illinois and eventually expanded his holdings to build the town, rescuing other slaves and bringing them there. Decades before the Civil War, blacks and whites lived and worked together.
Fennell says the Pike County Railroad Co. defied topography, efficiency, cost and even its own surveyors' advice to build a wide bypass.
At its peak in 1865, the town had about 160 residents. After the bypass was built in 1870, New Philadelphia declined and reverted to farmland. By the 1890s it was gone.
"The last explanation standing," Fennell writes, is that the railroad, based in slave-trading Hannibal, Mo., "did not want to see New Philadelphia thrive. ... This is an instance where racial ideology leads to a net loss for everyone."