Labrador Retrievers are some of the most popular dogs in the United States.  They're loyal, friendly, obedient, and make great family dogs.  However, while we do not see them as often, Labrador Retrievers are also used by the military and police as working dogs. The first ancestors of the Labrador Retriever originated on the island of Newfoundland, in what is now Newfoundland and Labrador, Canada.  The earliest were called St. John's Water Dogs, which were first bred around the 16th century.  Fast forward to the 1800s, the breed had almost completely disappeared from Canada but had evolved into the Labrador Retriever we see today.  Researchers suspect these dogs were the product of breeding together the original St. John's Water Dog with the Mastiff. The Labrador Retriever's keen sense of smell makes it a desirable search and rescue dog, tracker, and illegal- or explosive-substance detector.  Unlike some other breeds, which can become distracted while following a scent, Labrador Retrievers are known to be highly focused.  They will stay on a trail until they find what they're looking for.  This makes them invaluable assets to the military – especially when time is of the essence.