Ohio River Canalization Stamp
On October 19, 1929, the U.S. Post Office issued a 2¢ commemorative honoring the canalization of the Ohio River.
The 981-mile long Ohio River stretches from Pittsburgh, Pennsylvania to Cairo, Illinois, where it empties into the Mississippi River. It carries the most water by volume of all the Mississippi River tributaries. However, areas of the river became too shallow during the dry parts of the year, preventing steamboats from traveling the entire length.