The first half of the 20th century was a period of great change along the historic Ohio River corridor. It was then that the Ohio became the most heavily engineered river in the world, facilitating its use as an artery of commerce. It was also a period of great change in transportation as different means of travel appeared along the margins of this storied waterway. And it was the era of the picture postcard, in which postcard publishing companies chose views for the public to buy and share with family and friends via the United States Postal Service.