Developed in the United States, the American Water Spaniel is the Wisconsin state dog. The breed originated in the areas along the Fox River and its tributary the Wolf River during the early 19th century. Hunters needed a dog that could work on both land and water, a versatile hunter skilled at bringing in a variety of game. Hunters also wanted a hunting dog compact enough to be transported in a small skiff, one that was able to withstand Wisconsin's cold water temperatures. Breeds involved in the creation of the American Water Spaniel are thought to have included the English Water Spaniel, Irish Water Spaniel, Curly Coated Retriever, native Indian Dogs, the Poodle, and either the Sussex Spaniel or another type of field spaniel.
Due to Pfeifer's work, the breed was recognized by the United Kennel Club (UKC) as the American Water Spaniel in 1920, and by the Field Dog Stud Book in 1938. Dr. Pfeifer's own dog, named "Curly Pfeifer" was the first American Water Spaniel to be registered with UKC. John Scofield of Missouri and Thomas Brogdan of Rush Lake, Wisconsin worked together with the American Water Spaniel Club (AWSC), gaining the breed recognition with the American Kennel Club (AKC) in 1940. Prior to recognition by the AKC, the breed had not been shown in the show ring before.
The breed has links to the Boykin Spaniel, and is thought to have been the main breed used to develop the Boykin. The differences between the Boykin and the AWS are negligible with some dog historians suggesting that the original Boykin, called "Dumpy", who was found on the streets of Spartanburg, South Carolina, was actually an American Water Spaniel who had been misplaced in transit. However the breed clubs for the Boykin do not agree with this account.
The breed was made the state dog of Wisconsin in 1985. The American Water Spaniel remains a rare breed. During 1998 only 233 puppies were registered with the AKC, with an estimated 3,000 dogs in existence mostly around the Midwestern United States, in particular in Wisconsin, Minnesota and Michigan. In 2010, the breed was ranked 143rd most popular breed in the United States, out of 167 breeds. This is a decrease since 2000, when the breed was ranked 125th. The dogs are not classified specifically as either retrievers or as spaniels and so may not compete in AKC field trials, but may compete in AKC hunt tests (spaniel and retriever tests) and retriever hunting tests sponsored by the AWSC, the breed club in the United States. The American Water Spaniel Field Association was set up in 1993 by breed enthusiasts supporting AKC Spaniel classification and looking to provide field training opportunities to owners of the breed. In a vote held of members of the AWSC in 1999, they chose to keep the breed unclassified.