No company these days wants to be compared to the United States Postal Service. It is widely understood as America's most ponderous, most pathetic bureaucracy. After all, in an era of instant gratification, what is sadder than "snail mail"? 1908. | (The Smithsonian National Postal Museum via Flickr) But in the 19th and early 20th centuries, the national mail service was the country's beating heart of innovation. 1922 | An early airmail plane parked next to a U.S.