Why Are Dogs So Frequently Called "Fido"?

Although I don't remember ever meeting a dog named "Fido" that is the name that most frequently crops up as a generic name referring to any dog. Thus when a person says "She's living alone with only Fido for company" we know that he is talking about a woman and dog, although it is unlikely that dog is actually named Fido.
The linguistic origin of the name Fido is easy to trace. For instance the University of Notre Dame Latin dictionary defines fido as "to trust, believe, confide in" and several books on the origin of names defines it as meaning "I am faithful". In other words it is equivalent to calling a dog "Trusty" or "Faithful". However, the enduring popularity of the name as a representative of all dogs comes from its identification with a well loved celebrity.

Perhaps the President that has the greatest emotional appeal for Americans is the 16^th President, Abraham Lincoln. He is credited with preserving the Union during the Civil War and with introducing the emancipation proclamation that ended slavery in the country. Part of the charm that clings to his life story has to do with his rise from a humble beginning, the drama associated with his violent death at the hand of an assassin, and his distinctive personality, which demonstrated such humanity and humour. For historians and politicians his relevance has to do with his eloquence as a spokesman for democracy, in which he described how it was important to save the Union not only for its own sake, but also as an embodiment of the ideal of a democratic government based upon the principles of equal rights and justice.
Lincoln was twenty-one years of age when he moved to Illinois. There he took the bar examination to become a lawyer and opened a practice with a partner, William Herndon. In Lincoln's home there were often various dogs or cats which he claimed were just pets for the children. Herndon suggests that they were actually a therapeutic force in Lincoln's life. Lincoln was often subject to bouts of depression that would force him to stop work. His dogs and the occasional cat were lifelines that would pull him out of his despair. Herndon described the situation this way. "If exhausted from severe and long-continued thought, he had to touch the earth again to renew his strength. When this weariness set in he would stop thought, and get down with a little dog or kitten to recover; and when the recovery came he would push it aside to play with its own tail."

There was one particular dog who became important to Lincoln about five years before he was elected president. It was a floppy-eared, rough-coated dog of unknown ancestry or breed that he named "Fido". This dog was almost always with Lincoln and the people of Springfield would report that it was a common sight to see Lincoln walking down the street with Fido walking behind, carrying a parcel by the string tied around it. A regular stop for Lincoln was at Billy's Barbershop for a haircut. Fido would settle down to wait outside patiently, although he could easily be lured into a game involving jumping and twirling when young children came by and paid any particular attention to him.
When the news came that Lincoln had been elected president, he immediately began to plan the move to Washington DC. His wife, Mary Todd, however, who had no particular fondness for dogs, used this turn of events as an opportunity to rid herself of Fido for a while. She felt that Lincoln was too indulgent, letting the dog into the house even when he had dirty feet, letting him pester people at the dinner table and even letting jump up on to the furniture. "The public will not tolerate a dog, even the president's dog, if that animal soils the White House carpets, or damages the heritage furniture in that mansion. Those items are public property and are held in trust by the president and should not be despoiled by any animal."

Lincoln did not like to argue with his wife and sadly agreed to leave Fido behind. He, arranged to have Fido cared for by John Eddy Roll, a local carpenter, and his family, until he returned from his term in the White House. The fact that Mary Todd Lincoln might have been correct about her perceptions about the way that her husband treated the dog is shown by the instructions that Lincoln left with the Roll family. He specified that the family was never to scold Fido for entering the house with muddy paws. He was not to be tied up alone in the backyard. Fido was also supposed to be allowed to enter the house whenever he scratched at the door, or whenever the family sat down to meals. People were encouraged to feed Fido titbits while they ate in the dining room, since the new President explained that Fido was used to being given food by everyone sitting around Lincoln's table. Finally, to make Fido feel fully at home, Lincoln gave the Roll family his horsehair sofa, which was Fido's favorite piece of furniture.
Two of Lincoln's son's, Tad and Willy, were very upset about leaving Fido behind. However, still unwilling to fight with Mary over the presence of the dog, Lincoln took the boys and the dog over to the F.W. Ingmire's Photographic Studio. Mr. Ingmire draped a piece of fancy material over a washstand and placed Fido on top. He then took photographs of dog in several different poses, while the boys watched but did not participate. Photography was in its infancy then, and photographs were considered virtually miraculous. Each of the boys was then given a copy of a photo of Fido and told that this was just as good as having the dog with them in reality. The boys were unconvinced by their father's logic. Nonetheless,  Fido had now become the first Presidential dog ever to be photographed.
Even in 1863, in the days before mass media such as television and women's magazine covers, people were still keen to know all about famous people, and in America, nobody is more famous than the President. Some newspapers wrote about the President's pet, and several even published reproductions of the photograph of Fido. In a short time Fido was at the top of the list of most common dog names.
Following Lincoln's assassination in 1865, hundreds of heartbroken mourners from all over the country came to Springfield for the funeral. They gathered around the Lincoln home to pay their respects. On impulse, John Roll brought Fido back to his original home to meet with members of the grieving public. One who met Fido reported that "Touching the President's dog gave me the feeling that I had touched the man himself and seen his humanity. It brought me comfort in this time of grief as touching this dog must have brought the President comfort during his life."

 Unfortunately, Fido, like his master, would die a year later as a victim of an assassin. All of his life he had been surrounded by love, and hence Fido grew into a trusting and affectionate dog. Sadly, it was that friendly aspect that led to his tragic death in 1866. The big yellow rough-coated dog came across a man who appeared to be sleeping on the sidewalk in front of his home. He playfully approached the stranger and began to lick his face. The man, who was drunk at the time, awakened, saw the dog's open mouth near his face, and panicked. He drew a knife and stabbed what he imagined to be an assailant.
Fido did leave a legacy. In the same way that Lincoln became the symbol of common men everywhere who love democracy, Fido, or at least his name, goes on as a symbol of common dogs everywhere.