The concept of the electric fence was first described in Mark Twain's A Connecticut Yankee in King Arthur's Court, in 1889, as a defensive weapon.Electric fences were used to control livestock in the United States in the early 1930s, and electric fencing technology developed in both the United States and New Zealand.
An early application of the electric fence was developed in 1936–1937 by New Zealand inventor William "Bill" Gallagher Sr. Built from a car's ignition coil and a meccano set, Gallagher used the device to keep his horse from scratching itself against his car. Gallagher later started a company to improve and market the design "Gallagher, History".
In 1962, another New Zealand inventor, Doug Phillips, invented the non-shortable electric fence based on capacitor discharge. This significantly increased the range an electric fence could be used from a few hundred yards to 35 miles, and reduced the cost of fencing by more than 80%.[citation needed] The non-shortable electric fence was patented by Phillips and by 1964 was manufactured by Plastic Products, a New Zealand firm, under the name "Waikato Electric Fence."[citation needed] This idea was to move from ceramic to using a plastic insulator at the post. A variety of plastic insulators are now used on farms throughout the world today.
In 1969 a farmer, Robert B. Cox, in Adams County, Iowa, near Corning, Iowa invented an improved electric fence bracket and was issued a United States Patent No. 3,516,643 on June 23, 1970.
This bracket improved electric fences by keeping the wire high enough above the ground and far enough away from the fence to permit grass and weeds that may grow beneath the wire to be cut down by a mower. The brackets attached to the posts by what may be called a "pivot bind" or "torsion-lock." The weight of the bracket, the attached insulator and the electric wire attached to the insulator bind the bracket to the post.
Electric fences have improved significantly since the early days. Improvements include:
• Polyethylene insulators replacing porcelain insulators, beginning in the 1960s. Polyethylene is much cheaper than porcelain and is not as breakable.
• Improvements in electrical design of the fence energizer, often referred to as a "charger" (USA) or "fencer" (UK).
• Changes in laws. In some jurisdictions, certain types of electrical outputs for fences were unlawful until the 1950s or 1960s. In other areas, signage requirements and other restrictions limited usability.
• Introduction of high tensile (HT) steel fence wire in the 1970s in New Zealand and in the 1980s in the United States
• Introduction of synthetic webbing and rope-like fencing materials woven with fine conducting wires.
