The Scrambler was invented by Richard Hillman Harris of Georgia. The prototype was installed at Lakewood Fairgrounds, Atlanta, in 1938. Two more units were built and sold by Harris around 1939-1940, with one going to Virginia Beach. Harris obtained a patent (US patent 2259691) in 1941. Eli Bridge acquired or licensed the patent from Harris, but more than ten years elapsed before the ride went into production. Eli Bridge obtained a design patent for the passenger carrier (US design patent D176569), but the mechanical improvements that Eli Bridge made to the ride design were never patented.
Eli Bridge's website lists the Scrambler as their first non-ferris wheel ride, and dates it to 1955. However, the Eli Bridge Scrambler was listed in the ride survey in Billboard's Spring Issue in 1954, and the accompanying text indicates that it had been tested the previous fall. The ride was displayed at several fairs in the fall of 1954, with the ride operating as a concession. The first unit sold by Eli Bridge went to Funland Park in Miami, Florida, where it opened in 1955. By the end of 1955, 16 units were in operation. Eli Bridge had 230 willing buyers, but could only satisfy about 25 for the 1956 season. Their production remained fairly constant over the next few years, rising from 26 in 1960 to 30 in 1961. Eli Bridge has continued making Scramblers ever since.
That is obviously far too many units to list, so I will be content to mention only a few early installations:
Palisades installed a Scrambler in 1956, replacing their Rotor. The ride was owned by Lettie Harris of Atlanta, GA, and operated as a concession. Along with the Round-Up and the Paratrooper, it was removed after the 1960 season, apparently having passed the peak of its popularity.
Also in 1956, two Scramblers operated at the Canadian National Exhibition in Toronto.
Pacific Ocean Park installed a Scrambler in 1958 or 1959, which was named Jungle Whip.
Conneaut Lake Park added a Scrambler in 1959, while Cedar Point, Euclid Beach, Edgewater Park, Roseland Park, and Lake Winnepesaukah acquired Scramblers in 1960.
Success attracts competition, and several other makers attempted to capitalize on the popularity of the Scrambler (and on the excess of demand over Eli Bridge's production capacity) by selling similar rides. Garbrick Manufacturing introduced the Merry Mixer in 1957, and the Spindle was introduced by Vernon Garbrick in 1958. The Thomas Brothers manufactured the Whirly Bird (US patent 3078090). Hampton introduced the Rotation (a ride with similar action, but without the overhead supports) for the 1960 season, while Wisdom's Sizzler came considerably later.