In the 1850s the three-storey Randell Mill was built in the town of Blumberg (now Birdwood) and the adjoining four-storey Peerless Roller Mill was built in 1888, producing premium quality superfine flour. Electricity replaced the original Watt steam engine in the 1930s but the striking chimney was retained. By the late 1940s the Mill ceased production, replaced by newer and larger flour mills at Port Adelaide. The machinery was sold for scrap and the building abandoned.
In 1964 the building was purchased by Jack Kaines, along with fellow motoring enthusiast Len Vigar, to house their collections. The following year the Museum was opened to the public, rapidly developing over the next decade. The collection featured curios, collectibles, objets d'art, and an aircraft, alongside a motoring collection. A company of private shareholders purchased the Museum and, under the leadership of Gavin Sandford-Morgan, was promoted as the Birdwood Mill Pioneer, Art and Motor Museum.
In 1976 the South Australian Government purchased the Museum to avoid the collection from being dispersed. Since 1982 the Museum has been the responsibility of the History Trust of South Australia (now History SA). In December 1998 the new pavilion was opened with a focus on Australian Motoring History. The National Motor Museum has established a strong reputation as a centre of specialisation for Australian motor road transport history.
Current research has included the personal histories of some of the Museum's founders and collecting photographs documenting the original Museum.