Oliver began working at the age of thirteen as a messenger boy for the National Telegraph Company in Pittsburgh.

Oliver was involved in working with the Mesabi ore region near Lake Superior in Minnesota, spinning off the Oliver Iron Mining Company from his other interests in a venture with the Carnegie Steel Company.

The Lake Superior iron ore industry became the basis for United States Steel.

Oliver helped to develop improved processes for steel making, brought about a new and improved design for blast furnaces, and assisted in helping to finance several of Pittsburgh's large steel industries.

[1] Much of his energy was devoted to bringing new railroad routes into Pittsburgh (including the Pittsburgh and Lake Erie as well as the South Pennsylvania Railroad) and to providing new terminal belt lines for the city.