Thanks to the advertisement of 'Backyard Poultry' shown above, I learned that Baby Chicks can still be shipped by Mail. In fact, as the Poultry ad explains, because newborn chicks are still digesting the yolk sacks from the eggs, they are especially well equipped to survive, if they are kept warm and arrive within three days at the most.
Sadly, in the fall of 2020, when requested funds were withheld from the Postal Service, there was a slowdown of mail delivery, and thousands of baby birds died. This news was confirmed at USPS.com.
At the Postal site, I also discovered the requirements for shipping other live animals through the mail, such as Live Bees, Adult Birds, Live Scorpions, and Small, Harmless, Cold-Blooded Animals.
Who Knew!!! The requirements are very specific, including general requirements that they must be able to make the trip without need for food, water, or attention while in transport, they must not create sanitary problems, and they must not create obnoxious odors. If you are curious about more details, you may check the U.S. Postal Explorer.
As for the picture posted on face book by my friend, it may have truly depicted the mailing of a child, and that was briefly possible in 1913; however, the full reality of those cases would indicate that such mail delivery was not evidence of neglectful parents who took their child to the post office to be weighed and slapped the required stamps on their clothing and carelessly sent them on their way!