Yes, sending children with parcel service was actually a possibility in the land of opportunity, the USA! And it is another example for how genealogy can lead you towards bizarre and unbelievable stories from the past.
In 1913 and 1914 it was apparently possible - or not explicitly forbidden - to send human beings via parcel service. This was right after the postal service in the US started its parcel service on January 1st 1913. The service was received well. Within the first six months 300 million parcels have been sent.
It was something new to be able to send parcels. In the beginning it did not seem quite clear to the contemporaries what was included in this service. They produced boxes to be able to transport different items - even eggs. So, for instance, eggs were sent from St Louis, Missouri to Edwardsville, Illinois (26 miles apart). The eggs even came back to Missouri - just in a slightly different shape: a freshly baked cake!
One condition of the parcel service was that the maximum weight was 50 pounds. The conditions had a few loop holes, which were used accordingly. The terms and conditions did not state that little children could not be send via parcel service. It was stressful to travel with little children and tickets for the train were expensive, thus at least two families decided to send their child with the postal service to their relatives. A stamp was cheaper than a train ticket.
Another strange "parcel" was delivered from Grangeville, Idaho to Lewiston, Idaho on February 19, 1914. Both towns area bout 72 miles apart from each other. The parcel weighted 48.5 pounds and was just below the above mentioned maximum of 50 pounds. The content of said parcel was May Pierstorff, a little 5 year old girl.
Her parents send May to visit her grandparents. May was in fact transported by the train, not inside a parcel, but she did have a 53 cents stamp attached to her coat. She had to spend the whole journey in the mail compartment of the train. In Lewiston a mailmen delivered her to her grandmother's address and handed her over.
After stories like these were heard by the Postmaster General, he quickly issued a regulation that clearly stated, babies and children could not be sent with parcel service.