First we’ll take a look at the American Hairless Terrier, which to be fair is a more modern creation. The origin of the other hairless breeds (and may others) is unknown, but in the case of the American Hairless Terrier we know exactly how they came to be. In 1972 a hairless pup was born in a litter of Rat Terriers (which have only had AKC recognition since 2013) owned by Willie and Edwin Scott of Louisiana. They named the pup Josephine, and although she only produced three hairless pups in her lifetime they would become the foundation stock of the breed. The American Hairless Terrier has been assigned to the Terrier Group and also has a coated variety.
On the other side of the spectrum we have the Sloughi, an ancient sighthound that has existed in northern Africa for centuries, originally kept by the Berber people in what is now Morocco, Algeria, Tunisia and Libya. They are one of three native African sighthounds, the other two being the Azawakh and the Saluki, although it is unknown how closely they are related as each was kept by a different tribe. Once an extremely rare breed this new recognition should help boost their numbers. The Sloughi has been assigned to the Hound Group.