An example of a monopoly in the united states economy, past or present. construct a brief explanation of the monopoly and its impact on the market. your response should be about three hundred words. use primary and secondary sources, and cite them.

Past monopolies:
Standard Oil - incorporated under Standard Oil Trust which handled all oil production, transportation, refinement, and marketing. Holds 91% of oil production and 85% of its final sales in the United States Market in the early 1900s. 

 The company was sued for engaging in "“discriminatory practices in favor of the combination by railroad companies; restraint and monopolization by control of pipe lines, and unfair practices against competing pipe lines.” which led to its downfall.

Money believe but i may be wrong