Which measurement system is primarily used in the United States?

The primary measurement system used in the United States is the English System. This system includes units such as inches, feet, pounds, and gallons, which are commonly utilized in everyday life, construction, and various industries. The English System's predominance in the U.S. can be traced back to historical influences and standardization, making it the familiar system for most Americans.

While the Metric System is used in specific fields such as science and medicine, and the Imperial System is often associated with British measurements, they do not dominate in the same way as the English System does within the general context of American life. The term "American System" is not widely recognized as a formal measurement system, thus reinforcing the relevance of the English System as the correct choice in this context.