In 1901 Hart-Parr began production of their first tractor. It was rated at 17-30. The 17-30 models were built until 1906

Following the failure of the Little Devil, the Hart-Parr Company came out with a newly designed model, the 12-25.

With the merger of the Oliver Chilled Plow Works and the Hart-Parr Tractor Company, a completely new tractor was designed using ideas from both companies.

In 1937, the Hart-Parr Oliver 70 tractor took on a new streamlined look and became the Oliver 70.

In 1948 Oliver introduced a “New Fleet of Quality Tractors”.

The Super Series were merely updated version of the Fleetline tractors. However, during the Super production a few more models had been added to the line.

In 1958 the Super Series was upgraded to 3-digit series. These consisted of the 440, 550, 660, 770, 880, 990, 995 and 950.

In 1960 Oliver introduced two new models. The 1800 was a replacement for the 880 model.

In 1964 Oliver began to upgrade their previous models to the 50 Series.

In late 1969, Oliver introduced the 55 series of tractors.