The Old Courthouse in downtown St. Louis was the venue of one of the most celebrated cases in the United States judicial system - the one involving Dred Scott.* Scott was a Virginia slave who sued for his freedom in 1847 (his owner - an Army major named Emerson - lived in Missouri).
The courthouse, the tallest habitable building in Missouri until 1894, was built in 1839, in Greek revival style. Dred Scott's case was heard in the west wing of the building.
The case was eventually decided by the US Supreme Court, who ruled that slaves are considered property, and therefore have no claim for citizenship nor freedom. The ruling has far-reaching effects though, as it helped catalyzed the abolitionist movement and influenced Abraham Lincoln in his Emancipation Proclamation in 1863.
Today the courthouse is part of the Jefferson National Expansion Memorial park, which also includes the Gateway Arch and the Museum of Westward Expansion.
pic, from above: the Old Courthouse, where the case was heard; evidence of a dark past: a poster selling slaves, on display at the Museum of the Westward Expansion, in St. Louis.
*the name was familiar to me since college, as American history was one of the major subjects I have taken for my History course