Highlight
Central North America
The map shows the central section of the continent to illustrate the effect of the Louisiana Purchase (1803), the Lewis and Clark expedition, and the opening of the West. Ohio is shown with the seven ranges, the grid system that was started in eastern Ohio and was then used to map out many of the boundaries and counties across the rest of the country. The border between Arkansas and Missouri, the 36.30 parallel, is prominent because it was the boundary between the slave states and free states.
House Wing