why was the ohio river an important dividing line in the united state in the mid-1800?

Answer 1

Free states on the North, slave states on the south.

Answer 2

From its modest beginning in 1800, Ohio's coal production grew steadily but very slowly, never exceeding 1 million tons mined annually until the mid-1800's.During the first half of the 19th century, Ohio's early coal miners, primarily of English, Scottish, and Welsh descent, cut and loaded coal entirely by hand and moved the coal to local markets by means of wagons, carts, flatboats, and canal boats.

Completion of Ohio's canal system during the 1830's and 1840's allowed the development of distant markets for coal mined from the interior of the state. Gradually coal replaced wood as a fuel for home heating and cooking, boilers in salt production, blast furnaces, steam mills, sawmills, some oil and gas drilling rigs, and steamboats on the Great Lakes and the Ohio River. The first coal-fired steamboat, the Bazaleel Wells, was built in 1820 at Steubenville, Ohio. In addition, coal was distilled to produce coal oil for home lighting or gas for street lighting.