English Measurement in the United States

Why does the United States still use the English system? When was the last attempt to officially move to the metric system? Does the use of 
English measurement units put U.S. companies at a disadvantage when competing on international contracts? How has software solved the 
challenge? Give examples of engineering software that resolves this 
challenge. Research on the web and summarize your findings in three 
pages in APA format. You must include a title and reference page in 
which this is not included in the page count. The paper must be double space.